1dww
From Proteopedia
(New page: 200px<br /><applet load="1dww" size="450" color="white" frame="true" align="right" spinBox="true" caption="1dww, resolution 2.35Å" /> '''MURINE INDUCIBLE NIT...) |
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| - | [[Image:1dww.gif|left|200px]]<br /><applet load="1dww" size=" | + | [[Image:1dww.gif|left|200px]]<br /><applet load="1dww" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1dww, resolution 2.35Å" /> | caption="1dww, resolution 2.35Å" /> | ||
'''MURINE INDUCIBLE NITRIC OXIDE SYNTHASE OXYGENASE DIMER N-HYDROXYARGININE AND DIHYDROBIOPTERIN'''<br /> | '''MURINE INDUCIBLE NITRIC OXIDE SYNTHASE OXYGENASE DIMER N-HYDROXYARGININE AND DIHYDROBIOPTERIN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The oxygenase domain of the inducible nitric oxide synthase (iNOSox; | + | The oxygenase domain of the inducible nitric oxide synthase (iNOSox; residues 1-498) is a dimer that binds heme, L-arginine and tetrahydrobiopterin (H(4)B) and is the site for nitric oxide synthesis. We examined an N-terminal segment that contains a beta-hairpin hook, a zinc ligation center and part of the H(4)B-binding site for its role in dimerization, catalysis, and H(4)B and substrate interactions. Deletion mutagenesis identified the minimum catalytic core and indicated that an intact N-terminal beta-hairpin hook is essential. Alanine screening mutagenesis of conserved residues in the hook revealed five positions (K82, N83, D92, T93 and H95) where native properties were perturbed. Mutants fell into two classes: (i) incorrigible mutants that disrupt side-chain hydrogen bonds and packing interactions with the iNOSox C-terminus (N83, D92 and H95) and cause permanent defects in homodimer formation, H(4)B binding and activity; and (ii) reformable mutants that destabilize interactions of the residue main chain (K82 and T93) with the C-terminus and cause similar defects that were reversible with high concentrations of H(4)B. Heterodimers comprised of a hook-defective iNOSox mutant subunit and a full-length iNOS subunit were active in almost all cases. This suggests a mechanism whereby N-terminal hooks exchange between subunits in solution to stabilize the dimer. |
==About this Structure== | ==About this Structure== | ||
| - | 1DWW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with ZN, SO4, HEM, H2B and HAR as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Nitric-oxide_synthase Nitric-oxide synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.13.39 1.14.13.39] Full crystallographic information is available from [http:// | + | 1DWW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=HEM:'>HEM</scene>, <scene name='pdbligand=H2B:'>H2B</scene> and <scene name='pdbligand=HAR:'>HAR</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Nitric-oxide_synthase Nitric-oxide synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.13.39 1.14.13.39] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DWW OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Nitric-oxide synthase]] | [[Category: Nitric-oxide synthase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Arvai, A | + | [[Category: Arvai, A S.]] |
| - | [[Category: Crane, B | + | [[Category: Crane, B R.]] |
| - | [[Category: Getzoff, E | + | [[Category: Getzoff, E D.]] |
| - | [[Category: Stuehr, D | + | [[Category: Stuehr, D J.]] |
| - | [[Category: Tainer, J | + | [[Category: Tainer, J A.]] |
[[Category: H2B]] | [[Category: H2B]] | ||
[[Category: HAR]] | [[Category: HAR]] | ||
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[[Category: pterin]] | [[Category: pterin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:21:21 2008'' |
Revision as of 10:21, 21 February 2008
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MURINE INDUCIBLE NITRIC OXIDE SYNTHASE OXYGENASE DIMER N-HYDROXYARGININE AND DIHYDROBIOPTERIN
Overview
The oxygenase domain of the inducible nitric oxide synthase (iNOSox; residues 1-498) is a dimer that binds heme, L-arginine and tetrahydrobiopterin (H(4)B) and is the site for nitric oxide synthesis. We examined an N-terminal segment that contains a beta-hairpin hook, a zinc ligation center and part of the H(4)B-binding site for its role in dimerization, catalysis, and H(4)B and substrate interactions. Deletion mutagenesis identified the minimum catalytic core and indicated that an intact N-terminal beta-hairpin hook is essential. Alanine screening mutagenesis of conserved residues in the hook revealed five positions (K82, N83, D92, T93 and H95) where native properties were perturbed. Mutants fell into two classes: (i) incorrigible mutants that disrupt side-chain hydrogen bonds and packing interactions with the iNOSox C-terminus (N83, D92 and H95) and cause permanent defects in homodimer formation, H(4)B binding and activity; and (ii) reformable mutants that destabilize interactions of the residue main chain (K82 and T93) with the C-terminus and cause similar defects that were reversible with high concentrations of H(4)B. Heterodimers comprised of a hook-defective iNOSox mutant subunit and a full-length iNOS subunit were active in almost all cases. This suggests a mechanism whereby N-terminal hooks exchange between subunits in solution to stabilize the dimer.
About this Structure
1DWW is a Single protein structure of sequence from Mus musculus with , , , and as ligands. Active as Nitric-oxide synthase, with EC number 1.14.13.39 Full crystallographic information is available from OCA.
Reference
Inducible nitric oxide synthase: role of the N-terminal beta-hairpin hook and pterin-binding segment in dimerization and tetrahydrobiopterin interaction., Ghosh DK, Crane BR, Ghosh S, Wolan D, Gachhui R, Crooks C, Presta A, Tainer JA, Getzoff ED, Stuehr DJ, EMBO J. 1999 Nov 15;18(22):6260-70. PMID:10562538
Page seeded by OCA on Thu Feb 21 12:21:21 2008
Categories: Mus musculus | Nitric-oxide synthase | Single protein | Arvai, A S. | Crane, B R. | Getzoff, E D. | Stuehr, D J. | Tainer, J A. | H2B | HAR | HEM | SO4 | ZN | Dihydrobiopterin | Dimer | H2b | Heme | Intermediate | Nitric oxide monooxygenase | Pterin
