DOI: 10.1126/science.278.5337.425. The Structure of Nitric Oxide Synthase Oxygenase Domain and Inhibitor Complexes

The Structure of Nitric Oxide Synthase Oxygenase Domain and Inhibitor Complexes

10.1126/science.278.5337.425

Crossref journal-article

American Association for the Advancement of Science (AAAS)

Science (221)

Abstract

The nitric oxide synthase oxygenase domain (NOS ox ) oxidizes arginine to synthesize the cellular signal and defensive cytotoxin nitric oxide (NO). Crystal structures determined for cytokine-inducible NOS ox reveal an unusual fold and heme environment for stabilization of activated oxygen intermediates key for catalysis. A winged β sheet engenders a curved α-β domain resembling a baseball catcher's mitt with heme clasped in the palm. The location of exposed hydrophobic residues and the results of mutational analysis place the dimer interface adjacent to the heme-binding pocket. Juxtaposed hydrophobic O 2 - and polar l -arginine–binding sites occupied by imidazole and aminoguanidine, respectively, provide a template for designing dual-function inhibitors and imply substrate-assisted catalysis.

Bibliography

Crane, B. R., Arvai, A. S., Gachhui, R., Wu, C., Ghosh, D. K., Getzoff, E. D., Stuehr, D. J., & Tainer, J. A. (1997). The Structure of Nitric Oxide Synthase Oxygenase Domain and Inhibitor Complexes. Science, 278(5337), 425â431.

Authors 8

Brian R. Crane (first)
Andrew S. Arvai (additional)
Ratan Gachhui (additional)
Chaoqun Wu (additional)
Dipak K. Ghosh (additional)
Elizabeth D. Getzoff (additional)
Dennis J. Stuehr (additional)
John A. Tainer (additional)

References 63 Referenced 277

Moncada S., Higgs A., N. Eng. J. Med. 329, 2002 (1993); (10.1056/NEJM199312303292706) / N. Eng. J. Med. by Moncada S. (1993)
Nathan C., Xie Q., Cell 78, 915 (1994); (10.1016/0092-8674(94)90266-6) / Cell by Nathan C. (1994)
; H. H. Schmidt and U. Walter ibid. p. 919.
Griffith O. W., Stuehr D. J., Annu. Rev. Physiol. 57, 707 (1995). (10.1146/annurev.ph.57.030195.003423) / Annu. Rev. Physiol. by Griffith O. W. (1995)
Southan G. J., Szabo C., Biochem. Pharmacol. 51, 383 (1996). (10.1016/0006-2952(95)02099-3) / Biochem. Pharmacol. by Southan G. J. (1996)
B. Mayer and E. R. Werner Nauyn-Schmiedebergs Arch. Pharmacol. 351 453 (1995). (10.1007/BF00171035)
Masters B. S. S., et al., FASEB J. 10, 552 (1996). (10.1096/fasebj.10.5.8621055) / FASEB J. by Masters B. S. S. (1996)
E. J. Mueller P. J. Loida S. G. Sligar in Cytochrome P450: Structure Mechanism and Biochemistry P. R. Ortiz de Montellano Ed. (Plenum New York 1995) pp. 83–124. (10.1007/978-1-4757-2391-5_3)
10.1021/cr9500500
Marletta M., Cell 78, 927 (1994). (10.1016/0092-8674(94)90268-2) / Cell by Marletta M. (1994)
Stuehr D., Annu. Rev. Pharmacol. Toxicol. 18, 707 (1997). / Annu. Rev. Pharmacol. Toxicol. by Stuehr D. (1997)
Ghosh D. K., et al., Biochemistry 36, 10609 (1997). (10.1021/bi9702290) / Biochemistry by Ghosh D. K. (1997)
D. K. Ghosh R. Gachhui C. Wu N. Sennequier H. M. Abu-Soud D. J. Stuehr unpublished results.
Rodriguez-Crespo I., Moënne-Loccoz P., Loehr T. M., Ortiz de Montellano P. R., Biochemistry 36, 8530 (1997). (10.1021/bi970192j) / Biochemistry by Rodriguez-Crespo I. (1997)
Crystallization trials with dimeric full-length murine iNOS ox identified a favored truncation product with the NH 2 -terminal 114 residues removed conducive to crystal growth under select conditions. Inducible NOS ox Δ114 (including a fused COOH-terminal His 6 tag) was overexpressed in E. coli and purified by Ni-chelate chromatography as described previously (10 39). Orthorhombic iNOS ox Δ114 crystals of space group P 2 1 2 1 2 1 (cell dimensions 63.0 Å by 73.8 Å by 92.8 Å one molecule per asymmetric unit Matthews coefficient V M = 2.3 Å 3 /dalton solvent content = 48%) were grown at 32°C from drops containing iNOS ox Δ114 (10 mg/ml) 20 mM Hepes pH 7.6 50 mM imidazole/malate (IM/M) pH 5.0 2.5% saturated Na 2 SO 3 5% glycerol 0.5 mM dithiothreitol (DTT) and 8% PEG MW 4000 (polyethylene glycol of molecular weight 4000) (final pH of 6.5) by vapor diffusion against reservoir containing 100 mM IM/M pH 5.0 5% saturated Na 2 SO 3 and 16% PEG MW 4000. Cubic crystals (space group P 2 1 3 cell dimension of 147.5 Å V M = 3.8 Å 3 /dalton solvent content = 68%) of an iNOS ox Δ114– E. coli K-12 type I CAT 1:1 complex obtained by bimolecular crystallization were grown at 22°C from drops containing iNOS ox Δ114 (10 mg/ml) CAT (∼5 mg/ml) 20 mM Hepes pH 7.6 5% glycerol 0.5 mM DTT 50 mM IM/M pH 5.0 27.5% saturated Na 2 SO 4 (final pH of 6.5) by vapor diffusion against reservoir containing 100 mM IM/M pH 5.0 and 55% saturated Na 2 SO 4 . The aminoguanidine complex was formed by soaking an orthorhombic iNOS ox Δ114 crystal in 10 mM aminoguanidine carbonate 40 mM Hepes pH 7.9 and 12% PEG MW 6000 for 30 hours.
All native and derivative diffraction data (Table 1) were collected at the Stanford Synchrotron Radiation Laboratory (SSRL) on beam lines 7–1 and 9–1 at –170°C because weak diffraction of iNOS ox Δ114 precluded data collection from rotating anode x-ray sources. Efficient derivative screening at SSRL allowed extensive exploration of heavy atom concentration buffer conditions pH and soaking times for optimizing orthorhombic iNOS ox Δ114 heavy atom derivatives (Table 1). After data reduction with DENZO [
10.1016/S0076-6879(97)76066-X
] heavy atom positions were found with Patterson techniques confirmed by cross-Fourier maps calculated in XtalView (40) and then optimized by origin-removed Patterson refinement in HEAVY [
Terwilliger T. C., Eisenberg D., Acta Crystallogr. A39, 813 (1983); (10.1107/S0108767383001592) / Acta Crystallogr. by Terwilliger T. C. (1983)
]. Structure factor phases to 2.8 Å resolution calculated from isomorphous and anomalous differences with PHASES [W. Furey and S. Swaminathan Am. Cryst. Assoc. Mtg. Abstr. PA33 18 73 (1990)] [overall figure of merit (FOM) = 0.63] produced an initial experimental electron density map with an average amplitude-weighted phase error versus the final refined structure factors (〈Δφ〉) of 59.6° and a correlation coefficient between the experimental and final 2 F obs − F calc maps ( R c ) of 0.44. Density modification in DM [K. Cowtan Joint Collaborative Computational Project Number 4 (CCP4) and ESF-EACBM Newsletter on Protein Crystallography 31 34 (1994)] under the restraints of solvent flatness density histogram matching and Sayre's equation increased the overall FOM to 0.84 and R c to 0.55 and decreased 〈Δφ〉 to 50.9°. Model building into the DM-modified map with XFIT (40) produced a model containing 57% of total final scatterers (55% of which were fit to sequence and 45% to polyalanine) that was refined by maximum likelihood methods in REFMAC [G. Murshudov et al. Proceedings of The Daresbury Study Weekend p. 157 (1996)
CCP4 Acta Crystallogr. D50 760 (1994)] ( R cryst = 45% R free = 46%) and used for partial-model phase-combination with SIGMAA [ (10.1107/S0907444994003112)
10.1107/S0108767386099622
] to produce an improved electron density map ( R c = 0.59 〈Δφ〉 = 49.5°). Comparison of SIGMAA reduced-bias amplitudes to the measured amplitudes allowed FOM estimates for DM density modification of the partial-model phase-combined map further increasing R c to 0.65 and decreasing 〈Δφ〉 to 40.2°. After cycles of refinement and model building in XFIT and O [
Jones T. A., et al., ibid. A47, 110 (1991); / ibid. by Jones T. A. (1991)
] the resolution was extended to 2.5 Å against a model containing 85% of the final scatterers ( R cryst = 38.2% R free = 43.0%) which was improved by adding water molecules with ARP [V. S. Lamzin and K. S. Wilson ibid. D49 127 (1993)] applied in restrained mode among 50 cycles of recursive REFMAC refinement (on the final cycle R cryst = 28.6% R free = 36.0%). We completed refinement and resolution extension to 2.1 Å in X-PLOR [
10.1126/science.235.4787.458
] using the bulk solvent correction over cycles of rebuilding to σ A -weighted 2 F obs – F calc and F obs – F calc omit electron density maps (Table 1). The mobile loop regions of iNOS ox Δ114 (Fig. 3A) contribute to the refined model but give a high average individual atom isotropic thermal ( B ) value of 45.2 Å 2 (43.5 Å 2 for main- chain atoms 45.4 Å 2 for side-chain atoms and 33.7 Å 2 for the imidazole ligands) which agrees with overall B estimates from Wilson statistics. Discernible omit electron density and a decrease in R free determined if regions with high B values were included in the model.
For determining the structure of P 2 1 2 1 2 1 -AG the P 2 1 2 1 2 1 -IM model with imidazole and water molecules removed was refined against diffraction data for the isomorphous P 2 1 2 1 2 1 -AG crystal by positional refinement in X-PLOR to 2.3 Å resolution. After the entire molecule was rebuilt to omit maps aminoguanidine was oriented in the active center refined and verified by examining F obs – F calc electron density maps. A lower overall B value of 37.0 Å 2 (35.8 Å 2 for main-chain atoms 37.8 Å 2 for side-chain atoms 32.7 Å 2 for imidazole and 49.2 Å 2 for aminoguanidine) reflects more overall order in the orthorhombic aminoguanidine complex compared with the imidazole complex.
A 2.4 Å resolution iNOS ox Δ114 model refined in the orthorhombic space group ( R cryst = 26.0% R free = 34.0%) was orientated and fitted in the cubic crystal form by AMoRe [
10.1107/S0108767393007597
] giving a correlation coefficient of 0.36 and R cryst = 45.5% against 3.5 Å resolution P 2 1 3 diffraction data. Positional refinement to 2.9 Å resolution in REFMAC reduced R cryst to 41.3% and R free to 43.7%. A model of type III E. coli CAT refined to 1.75 Å resolution {3cla.pdb [
Gibbs M. R., et al., J. Mol. Biol. 213, 167 (1990); (10.1016/S0022-2836(05)80129-9) / J. Mol. Biol. by Gibbs M. R. (1990)
]} 46% identical in sequence to type I CAT was placed into the type I CAT electron density revealed by σ A -weighted 2 F obs – F calc and F obs – F calc electron density maps phased with the iNOS ox refined molecular replacement solution. Simulated annealing in X-PLOR to 2.8 Å resolution decreased R cryst to 26.5% and R free to 32.9%. Cycles of positional refinement rebuilding to omit electron density maps and resolution extension to 2.6 Å completed the model (Table 1). Disorder in the CAT molecule resulted in a higher overall B value (65.6 Å 2 for main-chain atoms 69.7 Å 2 for side-chain atoms 45.1 Å 2 for the imidazole ligands and 66.6 Å 2 overall) for the refined cubic model than for the orthorhombic models even though the overall B value for iNOS ox is similar in both crystal forms.
10.1006/jmbi.1993.1489
Bernstein F. C., et al., ibid. 112, 535 (1977). / ibid. by Bernstein F. C. (1977)
Sono M., Stuehr D. J., Ikeda-Saito M., Dawson J. H., J. Biol. Chem. 270, 19943 (1996). (10.1074/jbc.270.34.19943) / J. Biol. Chem. by Sono M. (1996)
Salerno J. C., McMillan K., Masters B. S. S., Biochemistry 35, 11839 (1996). (10.1021/bi953015w) / Biochemistry by Salerno J. C. (1996)
Xie Q. W., Leung M., Fuortes M., Sassa S., Nathan C., Proc. Natl. Acad. Sci. U.S.A. 93, 4891 (1996). (10.1073/pnas.93.10.4891) / Proc. Natl. Acad. Sci. U.S.A. by Xie Q. W. (1996)
Wang J., Stuehr D. J., Rousseau D. L., Biochemistry 36, 4595 (1997). (10.1021/bi962309u) / Biochemistry by Wang J. (1997)
Chen P. F., Tsai A. L., Berka V., Wu K., J. Biol. Chem. 272, 6114 (1997). (10.1074/jbc.272.10.6114) / J. Biol. Chem. by Chen P. F. (1997)
Gachhui R., et al., Biochemistry 36, 5097 (1997). (10.1021/bi970331x) / Biochemistry by Gachhui R. (1997)
D. Mansuy and J. P. Renaud in (6) pp. 537–574.
Sundaramoorthy M., Terner J., Poulos T. L., Structure 3, 1367 (1995). (10.1016/S0969-2126(01)00274-X) / Structure by Sundaramoorthy M. (1995)
Sennequier N., Stuehr D. J., Biochemistry 35, 5883 (1996). (10.1021/bi952844e) / Biochemistry by Sennequier N. (1996)
R. M. Chabin et al. ibid. p. 9567.
Wolff D. J., Lubeskie A., Arch. Biochem. Biophys. 316, 290 (1995). (10.1006/abbi.1995.1040) / Arch. Biochem. Biophys. by Wolff D. J. (1995)
Wang J., Rousseau D., Abu-Soud H. M., Stuehr D. J., Proc. Natl. Acad. Sci. U.S.A. 91, 10512 (1994). (10.1073/pnas.91.22.10512) / Proc. Natl. Acad. Sci. U.S.A. by Wang J. (1994)
Abu-Soud H. M., Gachhui R., Raushel F. M., Stuehr D. J., J. Biol. Chem. 271, 17349 (1997). (10.1074/jbc.272.28.17349) / J. Biol. Chem. by Abu-Soud H. M. (1997)
B. R. Crane et al. data not shown.
T. L. Poulos J. Cupp-Vickery H. Li in (6) pp. 125–150.
Wang M., Roberts D. L., Paschke R., Shea T. M., Masters B. S. S., Proc. Natl. Acad. Sci. U.S.A. 94, 8411 (1997). (10.1073/pnas.94.16.8411) / Proc. Natl. Acad. Sci. U.S.A. by Wang M. (1997)
Vaz A. D. N., Pernecky S. J., Raner G. M., Coon M. J., ibid. 93, 4644 (1996). / ibid. by Vaz A. D. N. (1996)
Goodin D. B., Davidson M. G., Roe J. A., Mauk A. G., Smith M., Biochemistry 30, 4953 (1991). (10.1021/bi00234a017) / Biochemistry by Goodin D. B. (1991)
Vitello L., Erman J., Miller M., Wang J., Kraut J., ibid. 32, 9807 (1993). / ibid. by Vitello L. (1993)
Brittain T., Blackmore R., Greenwood C., Thompson A. J., Eur. J. Biochem. 209, 793 (1992). (10.1111/j.1432-1033.1992.tb17350.x) / Eur. J. Biochem. by Brittain T. (1992)
Siddhanta U., et al., J. Biol. Chem. 271, 7309 (1996). (10.1074/jbc.271.13.7309) / J. Biol. Chem. by Siddhanta U. (1996)
McRee D. E., J. Mol. Graphics 10, 44 (1992). (10.1016/0263-7855(92)80022-6) / J. Mol. Graphics by McRee D. E. (1992)
These three NOS structures have excellent stereochemistry with 98.8% of all residues falling in the most favored or otherwise allowed regions of a Ramachandran φ/Ψ plot as defined by PROCHECK [
10.1107/S0021889892009944
]. No residues fall in disallowed regions. Nonbonded contacts were assessed with ERRAT [
Colovos C., Yeates T. O., Protein Sci. 2, 1511 (1993); (10.1002/pro.5560020916) / Protein Sci. by Colovos C. (1993)
] and found to be as likely or more likely than those of a representative group of high-resolution protein structures.
We thank C. Mol C. Putnam A. Bilwes and J. Noel for help with data collection A. Bilwes and D. Goodin for helpful discussions P. Clark T. Macke and J. Zhang for technical assistance and SSRL for use of data collection facilities. Supported by NIH grants HL58883 and CA53914. D.J.S. is an Established Investigator of the American Heart Association.

Dates

Type	When
Created	23 years, 1 month ago (July 27, 2002, 5:44 a.m.)
Deposited	1 year, 7 months ago (Jan. 13, 2024, 12:25 a.m.)
Indexed	4 weeks, 2 days ago (Aug. 7, 2025, 4:52 a.m.)
Issued	27 years, 10 months ago (Oct. 17, 1997)
Published	27 years, 10 months ago (Oct. 17, 1997)
Published Print	27 years, 10 months ago (Oct. 17, 1997)

Funders 0

None

BibTeX

@article{Crane_1997, title={The Structure of Nitric Oxide Synthase Oxygenase Domain and Inhibitor Complexes}, volume={278}, ISSN={1095-9203}, url={http://dx.doi.org/10.1126/science.278.5337.425}, DOI={10.1126/science.278.5337.425}, number={5337}, journal={Science}, publisher={American Association for the Advancement of Science (AAAS)}, author={Crane, Brian R. and Arvai, Andrew S. and Gachhui, Ratan and Wu, Chaoqun and Ghosh, Dipak K. and Getzoff, Elizabeth D. and Stuehr, Dennis J. and Tainer, John A.}, year={1997}, month=oct, pages={425–431} }

JSON

{
  "indexed": {
    "date-parts": [
      [
        2025,
        8,
        7
      ]
    ],
    "date-time": "2025-08-07T08:52:13Z",
    "timestamp": 1754556733250
  },
  "reference-count": 63,
  "publisher": "American Association for the Advancement of Science (AAAS)",
  "issue": "5337",
  "content-domain": {
    "domain": [],
    "crossmark-restriction": false
  },
  "published-print": {
    "date-parts": [
      [
        1997,
        10,
        17
      ]
    ]
  },
  "abstract": "<jats:p>\n            The nitric oxide synthase oxygenase domain (NOS\n            <jats:sub>ox</jats:sub>\n            ) oxidizes arginine to synthesize the cellular signal and defensive cytotoxin nitric oxide (NO). Crystal structures determined for cytokine-inducible NOS\n            <jats:sub>ox</jats:sub>\n            reveal an unusual fold and heme environment for stabilization of activated oxygen intermediates key for catalysis. A winged \u03b2 sheet engenders a curved \u03b1-\u03b2 domain resembling a baseball catcher's mitt with heme clasped in the palm. The location of exposed hydrophobic residues and the results of mutational analysis place the dimer interface adjacent to the heme-binding pocket. Juxtaposed hydrophobic O\n            <jats:sub>2</jats:sub>\n            - and polar\n            <jats:sc>l</jats:sc>\n            -arginine\u2013binding sites occupied by imidazole and aminoguanidine, respectively, provide a template for designing dual-function inhibitors and imply substrate-assisted catalysis.\n          </jats:p>",
  "DOI": "10.1126/science.278.5337.425",
  "type": "journal-article",
  "created": {
    "date-parts": [
      [
        2002,
        7,
        27
      ]
    ],
    "date-time": "2002-07-27T09:44:47Z",
    "timestamp": 1027763087000
  },
  "page": "425-431",
  "source": "Crossref",
  "is-referenced-by-count": 277,
  "title": "The Structure of Nitric Oxide Synthase Oxygenase Domain and Inhibitor Complexes",
  "prefix": "10.1126",
  "volume": "278",
  "author": [
    {
      "given": "Brian R.",
      "family": "Crane",
      "sequence": "first",
      "affiliation": [
        {
          "name": "B. R. Crane, A. S. Arvai, E. D. Getzoff, and J. A. Tainer are in the Department of Molecular Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. R. Gachhui, C. Wu, D. K. Ghosh, and D. J. Stuehr are in the Department of Immunology, Cleveland Clinic, Cleveland, OH 44106, USA."
        }
      ]
    },
    {
      "given": "Andrew S.",
      "family": "Arvai",
      "sequence": "additional",
      "affiliation": [
        {
          "name": "B. R. Crane, A. S. Arvai, E. D. Getzoff, and J. A. Tainer are in the Department of Molecular Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. R. Gachhui, C. Wu, D. K. Ghosh, and D. J. Stuehr are in the Department of Immunology, Cleveland Clinic, Cleveland, OH 44106, USA."
        }
      ]
    },
    {
      "given": "Ratan",
      "family": "Gachhui",
      "sequence": "additional",
      "affiliation": [
        {
          "name": "B. R. Crane, A. S. Arvai, E. D. Getzoff, and J. A. Tainer are in the Department of Molecular Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. R. Gachhui, C. Wu, D. K. Ghosh, and D. J. Stuehr are in the Department of Immunology, Cleveland Clinic, Cleveland, OH 44106, USA."
        }
      ]
    },
    {
      "given": "Chaoqun",
      "family": "Wu",
      "sequence": "additional",
      "affiliation": [
        {
          "name": "B. R. Crane, A. S. Arvai, E. D. Getzoff, and J. A. Tainer are in the Department of Molecular Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. R. Gachhui, C. Wu, D. K. Ghosh, and D. J. Stuehr are in the Department of Immunology, Cleveland Clinic, Cleveland, OH 44106, USA."
        }
      ]
    },
    {
      "given": "Dipak K.",
      "family": "Ghosh",
      "sequence": "additional",
      "affiliation": [
        {
          "name": "B. R. Crane, A. S. Arvai, E. D. Getzoff, and J. A. Tainer are in the Department of Molecular Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. R. Gachhui, C. Wu, D. K. Ghosh, and D. J. Stuehr are in the Department of Immunology, Cleveland Clinic, Cleveland, OH 44106, USA."
        }
      ]
    },
    {
      "given": "Elizabeth D.",
      "family": "Getzoff",
      "sequence": "additional",
      "affiliation": [
        {
          "name": "B. R. Crane, A. S. Arvai, E. D. Getzoff, and J. A. Tainer are in the Department of Molecular Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. R. Gachhui, C. Wu, D. K. Ghosh, and D. J. Stuehr are in the Department of Immunology, Cleveland Clinic, Cleveland, OH 44106, USA."
        }
      ]
    },
    {
      "given": "Dennis J.",
      "family": "Stuehr",
      "sequence": "additional",
      "affiliation": [
        {
          "name": "B. R. Crane, A. S. Arvai, E. D. Getzoff, and J. A. Tainer are in the Department of Molecular Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. R. Gachhui, C. Wu, D. K. Ghosh, and D. J. Stuehr are in the Department of Immunology, Cleveland Clinic, Cleveland, OH 44106, USA."
        }
      ]
    },
    {
      "given": "John A.",
      "family": "Tainer",
      "sequence": "additional",
      "affiliation": [
        {
          "name": "B. R. Crane, A. S. Arvai, E. D. Getzoff, and J. A. Tainer are in the Department of Molecular Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. R. Gachhui, C. Wu, D. K. Ghosh, and D. J. Stuehr are in the Department of Immunology, Cleveland Clinic, Cleveland, OH 44106, USA."
        }
      ]
    }
  ],
  "member": "221",
  "reference": [
    {
      "key": "e_1_3_2_2_2",
      "doi-asserted-by": "crossref",
      "first-page": "2002",
      "DOI": "10.1056/NEJM199312303292706",
      "volume": "329",
      "author": "Moncada S.",
      "year": "1993",
      "unstructured": "Moncada S., Higgs A., N. Eng. J. Med. 329, 2002 (1993);",
      "journal-title": "N. Eng. J. Med."
    },
    {
      "key": "e_1_3_2_2_3",
      "doi-asserted-by": "crossref",
      "first-page": "915",
      "DOI": "10.1016/0092-8674(94)90266-6",
      "volume": "78",
      "author": "Nathan C.",
      "year": "1994",
      "unstructured": "Nathan C., Xie Q., Cell 78, 915 (1994);",
      "journal-title": "Cell"
    },
    {
      "key": "e_1_3_2_2_4",
      "unstructured": "; H. H. Schmidt and U. Walter ibid. p. 919."
    },
    {
      "key": "e_1_3_2_3_2",
      "doi-asserted-by": "crossref",
      "first-page": "707",
      "DOI": "10.1146/annurev.ph.57.030195.003423",
      "volume": "57",
      "author": "Griffith O. W.",
      "year": "1995",
      "unstructured": "Griffith O. W., Stuehr D. J., Annu. Rev. Physiol. 57, 707 (1995).",
      "journal-title": "Annu. Rev. Physiol."
    },
    {
      "key": "e_1_3_2_4_2",
      "doi-asserted-by": "crossref",
      "first-page": "383",
      "DOI": "10.1016/0006-2952(95)02099-3",
      "volume": "51",
      "author": "Southan G. J.",
      "year": "1996",
      "unstructured": "Southan G. J., Szabo C., Biochem. Pharmacol. 51, 383 (1996).",
      "journal-title": "Biochem. Pharmacol."
    },
    {
      "key": "e_1_3_2_5_2",
      "doi-asserted-by": "crossref",
      "unstructured": "B. Mayer and E. R. Werner Nauyn-Schmiedebergs Arch. Pharmacol. 351 453 (1995).",
      "DOI": "10.1007/BF00171035"
    },
    {
      "key": "e_1_3_2_6_2",
      "doi-asserted-by": "crossref",
      "first-page": "552",
      "DOI": "10.1096/fasebj.10.5.8621055",
      "volume": "10",
      "author": "Masters B. S. S.",
      "year": "1996",
      "unstructured": "Masters B. S. S., et al., FASEB J. 10, 552 (1996).",
      "journal-title": "FASEB J."
    },
    {
      "key": "e_1_3_2_7_2",
      "doi-asserted-by": "crossref",
      "unstructured": "E. J. Mueller P. J. Loida S. G. Sligar in Cytochrome P450: Structure Mechanism and Biochemistry P. R. Ortiz de Montellano Ed. (Plenum New York 1995) pp. 83\u2013124.",
      "DOI": "10.1007/978-1-4757-2391-5_3"
    },
    {
      "key": "e_1_3_2_8_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1021/cr9500500"
    },
    {
      "key": "e_1_3_2_9_2",
      "doi-asserted-by": "crossref",
      "first-page": "927",
      "DOI": "10.1016/0092-8674(94)90268-2",
      "volume": "78",
      "author": "Marletta M.",
      "year": "1994",
      "unstructured": "Marletta M., Cell 78, 927 (1994).",
      "journal-title": "Cell"
    },
    {
      "key": "e_1_3_2_10_2",
      "first-page": "707",
      "volume": "18",
      "author": "Stuehr D.",
      "year": "1997",
      "unstructured": "Stuehr D., Annu. Rev. Pharmacol. Toxicol. 18, 707 (1997).",
      "journal-title": "Annu. Rev. Pharmacol. Toxicol."
    },
    {
      "key": "e_1_3_2_11_2",
      "doi-asserted-by": "crossref",
      "first-page": "10609",
      "DOI": "10.1021/bi9702290",
      "volume": "36",
      "author": "Ghosh D. K.",
      "year": "1997",
      "unstructured": "Ghosh D. K., et al., Biochemistry 36, 10609 (1997).",
      "journal-title": "Biochemistry"
    },
    {
      "key": "e_1_3_2_12_2",
      "unstructured": "D. K. Ghosh R. Gachhui C. Wu N. Sennequier H. M. Abu-Soud D. J. Stuehr unpublished results."
    },
    {
      "key": "e_1_3_2_13_2",
      "doi-asserted-by": "crossref",
      "first-page": "8530",
      "DOI": "10.1021/bi970192j",
      "volume": "36",
      "author": "Rodriguez-Crespo I.",
      "year": "1997",
      "unstructured": "Rodriguez-Crespo I., Mo\u00ebnne-Loccoz P., Loehr T. M., Ortiz de Montellano P. R., Biochemistry 36, 8530 (1997).",
      "journal-title": "Biochemistry"
    },
    {
      "key": "e_1_3_2_14_2",
      "unstructured": "Crystallization trials with dimeric full-length murine iNOS ox identified a favored truncation product with the NH 2 -terminal 114 residues removed conducive to crystal growth under select conditions. Inducible NOS ox \u0394114 (including a fused COOH-terminal His 6 tag) was overexpressed in E. coli and purified by Ni-chelate chromatography as described previously (10 39). Orthorhombic iNOS ox \u0394114 crystals of space group P 2 1 2 1 2 1 (cell dimensions 63.0 \u00c5 by 73.8 \u00c5 by 92.8 \u00c5 one molecule per asymmetric unit Matthews coefficient V M = 2.3 \u00c5 3 /dalton solvent content = 48%) were grown at 32\u00b0C from drops containing iNOS ox \u0394114 (10 mg/ml) 20 mM Hepes pH 7.6 50 mM imidazole/malate (IM/M) pH 5.0 2.5% saturated Na 2 SO 3 5% glycerol 0.5 mM dithiothreitol (DTT) and 8% PEG MW 4000 (polyethylene glycol of molecular weight 4000) (final pH of 6.5) by vapor diffusion against reservoir containing 100 mM IM/M pH 5.0 5% saturated Na 2 SO 3 and 16% PEG MW 4000. Cubic crystals (space group P 2 1 3 cell dimension of 147.5 \u00c5 V M = 3.8 \u00c5 3 /dalton solvent content = 68%) of an iNOS ox \u0394114\u2013 E. coli K-12 type I CAT 1:1 complex obtained by bimolecular crystallization were grown at 22\u00b0C from drops containing iNOS ox \u0394114 (10 mg/ml) CAT (\u223c5 mg/ml) 20 mM Hepes pH 7.6 5% glycerol 0.5 mM DTT 50 mM IM/M pH 5.0 27.5% saturated Na 2 SO 4 (final pH of 6.5) by vapor diffusion against reservoir containing 100 mM IM/M pH 5.0 and 55% saturated Na 2 SO 4 . The aminoguanidine complex was formed by soaking an orthorhombic iNOS ox \u0394114 crystal in 10 mM aminoguanidine carbonate 40 mM Hepes pH 7.9 and 12% PEG MW 6000 for 30 hours."
    },
    {
      "key": "e_1_3_2_15_2",
      "unstructured": "All native and derivative diffraction data (Table 1) were collected at the Stanford Synchrotron Radiation Laboratory (SSRL) on beam lines 7\u20131 and 9\u20131 at \u2013170\u00b0C because weak diffraction of iNOS ox \u0394114 precluded data collection from rotating anode x-ray sources. Efficient derivative screening at SSRL allowed extensive exploration of heavy atom concentration buffer conditions pH and soaking times for optimizing orthorhombic iNOS ox \u0394114 heavy atom derivatives (Table 1). After data reduction with DENZO ["
    },
    {
      "key": "e_1_3_2_15_3",
      "doi-asserted-by": "publisher",
      "DOI": "10.1016/S0076-6879(97)76066-X"
    },
    {
      "key": "e_1_3_2_15_4",
      "unstructured": "] heavy atom positions were found with Patterson techniques confirmed by cross-Fourier maps calculated in XtalView (40) and then optimized by origin-removed Patterson refinement in HEAVY ["
    },
    {
      "key": "e_1_3_2_15_5",
      "doi-asserted-by": "crossref",
      "first-page": "813",
      "DOI": "10.1107/S0108767383001592",
      "volume": "39",
      "author": "Terwilliger T. C.",
      "year": "1983",
      "unstructured": "Terwilliger T. C., Eisenberg D., Acta Crystallogr. A39, 813 (1983);",
      "journal-title": "Acta Crystallogr."
    },
    {
      "key": "#cr-split#-e_1_3_2_15_6.1",
      "unstructured": "]. Structure factor phases to 2.8 \u00c5 resolution calculated from isomorphous and anomalous differences with PHASES [W. Furey and S. Swaminathan Am. Cryst. Assoc. Mtg. Abstr. PA33 18 73 (1990)] [overall figure of merit (FOM) = 0.63] produced an initial experimental electron density map with an average amplitude-weighted phase error versus the final refined structure factors (\u3008\u0394\u03c6\u3009) of 59.6\u00b0 and a correlation coefficient between the experimental and final 2 F obs \u2212 F calc maps ( R c ) of 0.44. Density modification in DM [K. Cowtan Joint Collaborative Computational Project Number 4 (CCP4) and ESF-EACBM Newsletter on Protein Crystallography 31 34 (1994)] under the restraints of solvent flatness density histogram matching and Sayre's equation increased the overall FOM to 0.84 and R c to 0.55 and decreased \u3008\u0394\u03c6\u3009 to 50.9\u00b0. Model building into the DM-modified map with XFIT (40) produced a model containing 57% of total final scatterers (55% of which were fit to sequence and 45% to polyalanine) that was refined by maximum likelihood methods in REFMAC [G. Murshudov et al. Proceedings of The Daresbury Study Weekend p. 157 (1996)"
    },
    {
      "key": "#cr-split#-e_1_3_2_15_6.2",
      "doi-asserted-by": "crossref",
      "unstructured": "CCP4 Acta Crystallogr. D50 760 (1994)] ( R cryst = 45% R free = 46%) and used for partial-model phase-combination with SIGMAA [",
      "DOI": "10.1107/S0907444994003112"
    },
    {
      "key": "e_1_3_2_15_7",
      "doi-asserted-by": "publisher",
      "DOI": "10.1107/S0108767386099622"
    },
    {
      "key": "e_1_3_2_15_8",
      "unstructured": "] to produce an improved electron density map ( R c = 0.59 \u3008\u0394\u03c6\u3009 = 49.5\u00b0). Comparison of SIGMAA reduced-bias amplitudes to the measured amplitudes allowed FOM estimates for DM density modification of the partial-model phase-combined map further increasing R c to 0.65 and decreasing \u3008\u0394\u03c6\u3009 to 40.2\u00b0. After cycles of refinement and model building in XFIT and O ["
    },
    {
      "key": "e_1_3_2_15_9",
      "first-page": "110",
      "volume": "47",
      "author": "Jones T. A.",
      "year": "1991",
      "unstructured": "Jones T. A., et al., ibid. A47, 110 (1991);",
      "journal-title": "ibid."
    },
    {
      "key": "e_1_3_2_15_10",
      "unstructured": "] the resolution was extended to 2.5 \u00c5 against a model containing 85% of the final scatterers ( R cryst = 38.2% R free = 43.0%) which was improved by adding water molecules with ARP [V. S. Lamzin and K. S. Wilson ibid. D49 127 (1993)] applied in restrained mode among 50 cycles of recursive REFMAC refinement (on the final cycle R cryst = 28.6% R free = 36.0%). We completed refinement and resolution extension to 2.1 \u00c5 in X-PLOR ["
    },
    {
      "key": "e_1_3_2_15_11",
      "doi-asserted-by": "publisher",
      "DOI": "10.1126/science.235.4787.458"
    },
    {
      "key": "e_1_3_2_15_12",
      "unstructured": "] using the bulk solvent correction over cycles of rebuilding to \u03c3 A -weighted 2 F obs \u2013 F calc and F obs \u2013 F calc omit electron density maps (Table 1). The mobile loop regions of iNOS ox \u0394114 (Fig. 3A) contribute to the refined model but give a high average individual atom isotropic thermal ( B ) value of 45.2 \u00c5 2 (43.5 \u00c5 2 for main- chain atoms 45.4 \u00c5 2 for side-chain atoms and 33.7 \u00c5 2 for the imidazole ligands) which agrees with overall B estimates from Wilson statistics. Discernible omit electron density and a decrease in R free determined if regions with high B values were included in the model."
    },
    {
      "key": "e_1_3_2_16_2",
      "unstructured": "For determining the structure of P 2 1 2 1 2 1 -AG the P 2 1 2 1 2 1 -IM model with imidazole and water molecules removed was refined against diffraction data for the isomorphous P 2 1 2 1 2 1 -AG crystal by positional refinement in X-PLOR to 2.3 \u00c5 resolution. After the entire molecule was rebuilt to omit maps aminoguanidine was oriented in the active center refined and verified by examining F obs \u2013 F calc electron density maps. A lower overall B value of 37.0 \u00c5 2 (35.8 \u00c5 2 for main-chain atoms 37.8 \u00c5 2 for side-chain atoms 32.7 \u00c5 2 for imidazole and 49.2 \u00c5 2 for aminoguanidine) reflects more overall order in the orthorhombic aminoguanidine complex compared with the imidazole complex."
    },
    {
      "key": "e_1_3_2_17_2",
      "unstructured": "A 2.4 \u00c5 resolution iNOS ox \u0394114 model refined in the orthorhombic space group ( R cryst = 26.0% R free = 34.0%) was orientated and fitted in the cubic crystal form by AMoRe ["
    },
    {
      "key": "e_1_3_2_17_3",
      "doi-asserted-by": "publisher",
      "DOI": "10.1107/S0108767393007597"
    },
    {
      "key": "e_1_3_2_17_4",
      "unstructured": "] giving a correlation coefficient of 0.36 and R cryst = 45.5% against 3.5 \u00c5 resolution P 2 1 3 diffraction data. Positional refinement to 2.9 \u00c5 resolution in REFMAC reduced R cryst to 41.3% and R free to 43.7%. A model of type III E. coli CAT refined to 1.75 \u00c5 resolution {3cla.pdb ["
    },
    {
      "key": "e_1_3_2_17_5",
      "doi-asserted-by": "crossref",
      "first-page": "167",
      "DOI": "10.1016/S0022-2836(05)80129-9",
      "volume": "213",
      "author": "Gibbs M. R.",
      "year": "1990",
      "unstructured": "Gibbs M. R., et al., J. Mol. Biol. 213, 167 (1990);",
      "journal-title": "J. Mol. Biol."
    },
    {
      "key": "e_1_3_2_17_6",
      "unstructured": "]} 46% identical in sequence to type I CAT was placed into the type I CAT electron density revealed by \u03c3 A -weighted 2 F obs \u2013 F calc and F obs \u2013 F calc electron density maps phased with the iNOS ox refined molecular replacement solution. Simulated annealing in X-PLOR to 2.8 \u00c5 resolution decreased R cryst to 26.5% and R free to 32.9%. Cycles of positional refinement rebuilding to omit electron density maps and resolution extension to 2.6 \u00c5 completed the model (Table 1). Disorder in the CAT molecule resulted in a higher overall B value (65.6 \u00c5 2 for main-chain atoms 69.7 \u00c5 2 for side-chain atoms 45.1 \u00c5 2 for the imidazole ligands and 66.6 \u00c5 2 overall) for the refined cubic model than for the orthorhombic models even though the overall B value for iNOS ox is similar in both crystal forms."
    },
    {
      "key": "e_1_3_2_18_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1006/jmbi.1993.1489"
    },
    {
      "key": "e_1_3_2_19_2",
      "first-page": "535",
      "volume": "112",
      "author": "Bernstein F. C.",
      "year": "1977",
      "unstructured": "Bernstein F. C., et al., ibid. 112, 535 (1977).",
      "journal-title": "ibid."
    },
    {
      "key": "e_1_3_2_20_2",
      "doi-asserted-by": "crossref",
      "first-page": "19943",
      "DOI": "10.1074/jbc.270.34.19943",
      "volume": "270",
      "author": "Sono M.",
      "year": "1996",
      "unstructured": "Sono M., Stuehr D. J., Ikeda-Saito M., Dawson J. H., J. Biol. Chem. 270, 19943 (1996).",
      "journal-title": "J. Biol. Chem."
    },
    {
      "key": "e_1_3_2_21_2",
      "doi-asserted-by": "crossref",
      "first-page": "11839",
      "DOI": "10.1021/bi953015w",
      "volume": "35",
      "author": "Salerno J. C.",
      "year": "1996",
      "unstructured": "Salerno J. C., McMillan K., Masters B. S. S., Biochemistry 35, 11839 (1996).",
      "journal-title": "Biochemistry"
    },
    {
      "key": "e_1_3_2_22_2",
      "doi-asserted-by": "crossref",
      "first-page": "4891",
      "DOI": "10.1073/pnas.93.10.4891",
      "volume": "93",
      "author": "Xie Q. W.",
      "year": "1996",
      "unstructured": "Xie Q. W., Leung M., Fuortes M., Sassa S., Nathan C., Proc. Natl. Acad. Sci. U.S.A. 93, 4891 (1996).",
      "journal-title": "Proc. Natl. Acad. Sci. U.S.A."
    },
    {
      "key": "e_1_3_2_23_2",
      "doi-asserted-by": "crossref",
      "first-page": "4595",
      "DOI": "10.1021/bi962309u",
      "volume": "36",
      "author": "Wang J.",
      "year": "1997",
      "unstructured": "Wang J., Stuehr D. J., Rousseau D. L., Biochemistry 36, 4595 (1997).",
      "journal-title": "Biochemistry"
    },
    {
      "key": "e_1_3_2_24_2",
      "doi-asserted-by": "crossref",
      "first-page": "6114",
      "DOI": "10.1074/jbc.272.10.6114",
      "volume": "272",
      "author": "Chen P. F.",
      "year": "1997",
      "unstructured": "Chen P. F., Tsai A. L., Berka V., Wu K., J. Biol. Chem. 272, 6114 (1997).",
      "journal-title": "J. Biol. Chem."
    },
    {
      "key": "e_1_3_2_25_2",
      "doi-asserted-by": "crossref",
      "first-page": "5097",
      "DOI": "10.1021/bi970331x",
      "volume": "36",
      "author": "Gachhui R.",
      "year": "1997",
      "unstructured": "Gachhui R., et al., Biochemistry 36, 5097 (1997).",
      "journal-title": "Biochemistry"
    },
    {
      "key": "e_1_3_2_26_2",
      "unstructured": "D. Mansuy and J. P. Renaud in (6) pp. 537\u2013574."
    },
    {
      "key": "e_1_3_2_27_2",
      "doi-asserted-by": "crossref",
      "first-page": "1367",
      "DOI": "10.1016/S0969-2126(01)00274-X",
      "volume": "3",
      "author": "Sundaramoorthy M.",
      "year": "1995",
      "unstructured": "Sundaramoorthy M., Terner J., Poulos T. L., Structure 3, 1367 (1995).",
      "journal-title": "Structure"
    },
    {
      "key": "e_1_3_2_28_2",
      "doi-asserted-by": "crossref",
      "first-page": "5883",
      "DOI": "10.1021/bi952844e",
      "volume": "35",
      "author": "Sennequier N.",
      "year": "1996",
      "unstructured": "Sennequier N., Stuehr D. J., Biochemistry 35, 5883 (1996).",
      "journal-title": "Biochemistry"
    },
    {
      "key": "e_1_3_2_29_2",
      "unstructured": "R. M. Chabin et al. ibid. p. 9567."
    },
    {
      "key": "e_1_3_2_30_2",
      "doi-asserted-by": "crossref",
      "first-page": "290",
      "DOI": "10.1006/abbi.1995.1040",
      "volume": "316",
      "author": "Wolff D. J.",
      "year": "1995",
      "unstructured": "Wolff D. J., Lubeskie A., Arch. Biochem. Biophys. 316, 290 (1995).",
      "journal-title": "Arch. Biochem. Biophys."
    },
    {
      "key": "e_1_3_2_31_2",
      "doi-asserted-by": "crossref",
      "first-page": "10512",
      "DOI": "10.1073/pnas.91.22.10512",
      "volume": "91",
      "author": "Wang J.",
      "year": "1994",
      "unstructured": "Wang J., Rousseau D., Abu-Soud H. M., Stuehr D. J., Proc. Natl. Acad. Sci. U.S.A. 91, 10512 (1994).",
      "journal-title": "Proc. Natl. Acad. Sci. U.S.A."
    },
    {
      "key": "e_1_3_2_32_2",
      "doi-asserted-by": "crossref",
      "first-page": "17349",
      "DOI": "10.1074/jbc.272.28.17349",
      "volume": "271",
      "author": "Abu-Soud H. M.",
      "year": "1997",
      "unstructured": "Abu-Soud H. M., Gachhui R., Raushel F. M., Stuehr D. J., J. Biol. Chem. 271, 17349 (1997).",
      "journal-title": "J. Biol. Chem."
    },
    {
      "key": "e_1_3_2_33_2",
      "unstructured": "B. R. Crane et al. data not shown."
    },
    {
      "key": "e_1_3_2_34_2",
      "unstructured": "T. L. Poulos J. Cupp-Vickery H. Li in (6) pp. 125\u2013150."
    },
    {
      "key": "e_1_3_2_35_2",
      "doi-asserted-by": "crossref",
      "first-page": "8411",
      "DOI": "10.1073/pnas.94.16.8411",
      "volume": "94",
      "author": "Wang M.",
      "year": "1997",
      "unstructured": "Wang M., Roberts D. L., Paschke R., Shea T. M., Masters B. S. S., Proc. Natl. Acad. Sci. U.S.A. 94, 8411 (1997).",
      "journal-title": "Proc. Natl. Acad. Sci. U.S.A."
    },
    {
      "key": "e_1_3_2_36_2",
      "first-page": "4644",
      "volume": "93",
      "author": "Vaz A. D. N.",
      "year": "1996",
      "unstructured": "Vaz A. D. N., Pernecky S. J., Raner G. M., Coon M. J., ibid. 93, 4644 (1996).",
      "journal-title": "ibid."
    },
    {
      "key": "e_1_3_2_37_2",
      "doi-asserted-by": "crossref",
      "first-page": "4953",
      "DOI": "10.1021/bi00234a017",
      "volume": "30",
      "author": "Goodin D. B.",
      "year": "1991",
      "unstructured": "Goodin D. B., Davidson M. G., Roe J. A., Mauk A. G., Smith M., Biochemistry 30, 4953 (1991).",
      "journal-title": "Biochemistry"
    },
    {
      "key": "e_1_3_2_38_2",
      "first-page": "9807",
      "volume": "32",
      "author": "Vitello L.",
      "year": "1993",
      "unstructured": "Vitello L., Erman J., Miller M., Wang J., Kraut J., ibid. 32, 9807 (1993).",
      "journal-title": "ibid."
    },
    {
      "key": "e_1_3_2_39_2",
      "doi-asserted-by": "crossref",
      "first-page": "793",
      "DOI": "10.1111/j.1432-1033.1992.tb17350.x",
      "volume": "209",
      "author": "Brittain T.",
      "year": "1992",
      "unstructured": "Brittain T., Blackmore R., Greenwood C., Thompson A. J., Eur. J. Biochem. 209, 793 (1992).",
      "journal-title": "Eur. J. Biochem."
    },
    {
      "key": "e_1_3_2_40_2",
      "doi-asserted-by": "crossref",
      "first-page": "7309",
      "DOI": "10.1074/jbc.271.13.7309",
      "volume": "271",
      "author": "Siddhanta U.",
      "year": "1996",
      "unstructured": "Siddhanta U., et al., J. Biol. Chem. 271, 7309 (1996).",
      "journal-title": "J. Biol. Chem."
    },
    {
      "key": "e_1_3_2_41_2",
      "doi-asserted-by": "crossref",
      "first-page": "44",
      "DOI": "10.1016/0263-7855(92)80022-6",
      "volume": "10",
      "author": "McRee D. E.",
      "year": "1992",
      "unstructured": "McRee D. E., J. Mol. Graphics 10, 44 (1992).",
      "journal-title": "J. Mol. Graphics"
    },
    {
      "key": "e_1_3_2_42_2",
      "unstructured": "These three NOS structures have excellent stereochemistry with 98.8% of all residues falling in the most favored or otherwise allowed regions of a Ramachandran \u03c6/\u03a8 plot as defined by PROCHECK ["
    },
    {
      "key": "e_1_3_2_42_3",
      "doi-asserted-by": "publisher",
      "DOI": "10.1107/S0021889892009944"
    },
    {
      "key": "e_1_3_2_42_4",
      "unstructured": "]. No residues fall in disallowed regions. Nonbonded contacts were assessed with ERRAT ["
    },
    {
      "key": "e_1_3_2_42_5",
      "doi-asserted-by": "crossref",
      "first-page": "1511",
      "DOI": "10.1002/pro.5560020916",
      "volume": "2",
      "author": "Colovos C.",
      "year": "1993",
      "unstructured": "Colovos C., Yeates T. O., Protein Sci. 2, 1511 (1993);",
      "journal-title": "Protein Sci."
    },
    {
      "key": "e_1_3_2_42_6",
      "unstructured": "] and found to be as likely or more likely than those of a representative group of high-resolution protein structures."
    },
    {
      "key": "e_1_3_2_43_2",
      "unstructured": "We thank C. Mol C. Putnam A. Bilwes and J. Noel for help with data collection A. Bilwes and D. Goodin for helpful discussions P. Clark T. Macke and J. Zhang for technical assistance and SSRL for use of data collection facilities. Supported by NIH grants HL58883 and CA53914. D.J.S. is an Established Investigator of the American Heart Association."
    }
  ],
  "container-title": "Science",
  "original-title": [],
  "language": "en",
  "link": [
    {
      "URL": "https://www.science.org/doi/pdf/10.1126/science.278.5337.425",
      "content-type": "unspecified",
      "content-version": "vor",
      "intended-application": "similarity-checking"
    }
  ],
  "deposited": {
    "date-parts": [
      [
        2024,
        1,
        13
      ]
    ],
    "date-time": "2024-01-13T05:25:55Z",
    "timestamp": 1705123555000
  },
  "score": 1,
  "resource": {
    "primary": {
      "URL": "https://www.science.org/doi/10.1126/science.278.5337.425"
    }
  },
  "subtitle": [],
  "short-title": [],
  "issued": {
    "date-parts": [
      [
        1997,
        10,
        17
      ]
    ]
  },
  "references-count": 63,
  "journal-issue": {
    "issue": "5337",
    "published-print": {
      "date-parts": [
        [
          1997,
          10,
          17
        ]
      ]
    }
  },
  "alternative-id": [
    "10.1126/science.278.5337.425"
  ],
  "URL": "http://dx.doi.org/10.1126/science.278.5337.425",
  "relation": {},
  "ISSN": [
    "0036-8075",
    "1095-9203"
  ],
  "subject": [],
  "container-title-short": "Science",
  "published": {
    "date-parts": [
      [
        1997,
        10,
        17
      ]
    ]
  }
}