From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
| Line 1: |
Line 1: |
| - | [[Image:1zds.gif|left|200px]] | + | {{Seed}} |
| | + | [[Image:1zds.png|left|200px]] |
| | | | |
| | <!-- | | <!-- |
| Line 9: |
Line 10: |
| | {{STRUCTURE_1zds| PDB=1zds | SCENE= }} | | {{STRUCTURE_1zds| PDB=1zds | SCENE= }} |
| | | | |
| - | '''Crystal Structure of Met150Gly AfNiR with Acetamide Bound'''
| + | ===Crystal Structure of Met150Gly AfNiR with Acetamide Bound=== |
| | | | |
| | | | |
| - | ==Overview==
| + | <!-- |
| - | In Cu-containing nitrite reductase from Alcaligenes faecalis S-6 the axial methionine ligand of the type-1 site was replaced (M150G) to make the copper ion accessible to external ligands that might affect the enzyme's catalytic activity. The type-1 site optical spectrum of M150G (A(460)/A(600)=0.71) differs significantly from that of the native nitrite reductase (A(460)/A(600)=1.3). The midpoint potential of the type-1 site of nitrite reductase M150G (E(M)=312(+/-5)mV versus hydrogen) is higher than that of the native enzyme (E(M)=213(+/-5)mV). M150G has a lower catalytic activity (k(cat)=133(+/-6)s(-1)) than the wild-type nitrite reductase (k(cat)=416(+/-10)s(-1)). The binding of external ligands to M150G restores spectral properties, midpoint potential (E(M)<225mV), and catalytic activity (k(cat)=374(+/-28)s(-1)). Also the M150H (A(460)/A(600)=7.7, E(M)=104(+/-5)mV, k(cat)=0.099(+/-0.006)s(-1)) and M150T (A(460)/A(600)=0.085, E(M)=340(+/-5)mV, k(cat)=126(+/-2)s(-1)) variants were characterized. Crystal structures show that the ligands act as allosteric effectors by displacing Met62, which moves to bind to the Cu in the position emptied by the M150G mutation. The reconstituted type-1 site has an otherwise unaltered geometry. The observation that removal of an endogenous ligand can introduce allosteric control in a redox enzyme suggests potential for structural and functional flexibility of copper-containing redox sites.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_16574144}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 16574144 is the PubMed ID number. |
| | + | --> |
| | + | {{ABSTRACT_PUBMED_16574144}} |
| | | | |
| | ==About this Structure== | | ==About this Structure== |
| Line 31: |
Line 35: |
| | [[Category: Metal-binding]] | | [[Category: Metal-binding]] |
| | [[Category: Nitrate assimiliation]] | | [[Category: Nitrate assimiliation]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 17:30:19 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 14:34:49 2008'' |
Revision as of 11:34, 28 July 2008
Template:STRUCTURE 1zds
Crystal Structure of Met150Gly AfNiR with Acetamide Bound
Template:ABSTRACT PUBMED 16574144
About this Structure
1ZDS is a Single protein structure of sequence from Alcaligenes faecalis. Full crystallographic information is available from OCA.
Reference
A rearranging ligand enables allosteric control of catalytic activity in copper-containing nitrite reductase., Wijma HJ, Macpherson I, Alexandre M, Diederix RE, Canters GW, Murphy ME, Verbeet MP, J Mol Biol. 2006 May 12;358(4):1081-93. Epub 2006 Mar 6. PMID:16574144
Page seeded by OCA on Mon Jul 28 14:34:49 2008
