1t6i
From Proteopedia
(New page: 200px<br /><applet load="1t6i" size="450" color="white" frame="true" align="right" spinBox="true" caption="1t6i, resolution 2.81Å" /> '''Nickel Superoxide Di...) |
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| - | [[Image:1t6i.jpg|left|200px]]<br /><applet load="1t6i" size=" | + | [[Image:1t6i.jpg|left|200px]]<br /><applet load="1t6i" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1t6i, resolution 2.81Å" /> | caption="1t6i, resolution 2.81Å" /> | ||
'''Nickel Superoxide Dismutase (NiSOD) Apo Structure'''<br /> | '''Nickel Superoxide Dismutase (NiSOD) Apo Structure'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The 1.30 A resolution crystal structure of nickel superoxide dismutase | + | The 1.30 A resolution crystal structure of nickel superoxide dismutase (NiSOD) identifies a novel SOD fold, assembly, and Ni active site. NiSOD is a hexameric assembly of right-handed 4-helix bundles of up-down-up-down topology with N-terminal hooks chelating the active site Ni ions. This newly identified nine-residue Ni-hook structural motif (His-Cys-X-X-Pro-Cys-Gly-X-Tyr) provides almost all interactions critical for metal binding and catalysis, and thus will likely be diagnostic of NiSODs. Conserved lysine residues are positioned for electrostatic guidance of the superoxide anion to the narrow active site channel. Apo structures show that the Ni-hook motif is unfolded prior to metal binding. The active site Ni geometry cycles from square planar Ni(II), with thiolate (Cys2 and Cys6) and backbone nitrogen (His1 and Cys2) ligands, to square pyramidal Ni(III) with an added axial His1 side chain ligand, consistent with electron paramagentic resonance spectroscopy. Analyses of the three NiSOD structures and comparisons to the Cu,Zn and Mn/Fe SODs support specific molecular mechanisms for NiSOD maturation and catalysis, and identify important structure-function relationships conserved among SODs. |
==About this Structure== | ==About this Structure== | ||
| - | 1T6I is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_coelicolor Streptomyces coelicolor]. Active as [http://en.wikipedia.org/wiki/Superoxide_dismutase Superoxide dismutase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.15.1.1 1.15.1.1] Full crystallographic information is available from [http:// | + | 1T6I is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_coelicolor Streptomyces coelicolor]. Active as [http://en.wikipedia.org/wiki/Superoxide_dismutase Superoxide dismutase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.15.1.1 1.15.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T6I OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Streptomyces coelicolor]] | [[Category: Streptomyces coelicolor]] | ||
[[Category: Superoxide dismutase]] | [[Category: Superoxide dismutase]] | ||
| - | [[Category: Barondeau, D | + | [[Category: Barondeau, D P.]] |
| - | [[Category: Bruns, C | + | [[Category: Bruns, C K.]] |
| - | [[Category: Getzoff, E | + | [[Category: Getzoff, E D.]] |
| - | [[Category: Kassmann, C | + | [[Category: Kassmann, C J.]] |
| - | [[Category: Tainer, J | + | [[Category: Tainer, J A.]] |
[[Category: 4-helix bundle]] | [[Category: 4-helix bundle]] | ||
[[Category: apo]] | [[Category: apo]] | ||
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[[Category: superoxide dismutase]] | [[Category: superoxide dismutase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:10:26 2008'' |
Revision as of 13:10, 21 February 2008
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Nickel Superoxide Dismutase (NiSOD) Apo Structure
Overview
The 1.30 A resolution crystal structure of nickel superoxide dismutase (NiSOD) identifies a novel SOD fold, assembly, and Ni active site. NiSOD is a hexameric assembly of right-handed 4-helix bundles of up-down-up-down topology with N-terminal hooks chelating the active site Ni ions. This newly identified nine-residue Ni-hook structural motif (His-Cys-X-X-Pro-Cys-Gly-X-Tyr) provides almost all interactions critical for metal binding and catalysis, and thus will likely be diagnostic of NiSODs. Conserved lysine residues are positioned for electrostatic guidance of the superoxide anion to the narrow active site channel. Apo structures show that the Ni-hook motif is unfolded prior to metal binding. The active site Ni geometry cycles from square planar Ni(II), with thiolate (Cys2 and Cys6) and backbone nitrogen (His1 and Cys2) ligands, to square pyramidal Ni(III) with an added axial His1 side chain ligand, consistent with electron paramagentic resonance spectroscopy. Analyses of the three NiSOD structures and comparisons to the Cu,Zn and Mn/Fe SODs support specific molecular mechanisms for NiSOD maturation and catalysis, and identify important structure-function relationships conserved among SODs.
About this Structure
1T6I is a Single protein structure of sequence from Streptomyces coelicolor. Active as Superoxide dismutase, with EC number 1.15.1.1 Full crystallographic information is available from OCA.
Reference
Nickel superoxide dismutase structure and mechanism., Barondeau DP, Kassmann CJ, Bruns CK, Tainer JA, Getzoff ED, Biochemistry. 2004 Jun 29;43(25):8038-47. PMID:15209499
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