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2f9s
From Proteopedia
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2nd Crystal Structure Of A Soluble Domain Of ResA In The Oxidised Form
Overview
The covalent attachment of heme cofactors to the apo-polypeptides via, thioether bonds is unique to the maturation of c-type cytochromes. A, number of thiol-disulfide oxidoreductases prepare the apocytochrome for, heme insertion in system I and II cytochrome c maturation. Although most, thiol-disulfide oxidoreductases are nonspecific, the less common, specific, thiol-disulfide oxidoreductases may be key to directing the usage of, electrons. Here we demonstrate that unlike other thiol-disulfide, oxidoreductases, the protein responsible for reducing oxidized, apocytochrome c in Bacillus subtilis, ResA, is specific for cytochrome, c550 and utilizes alternate conformations to recognize redox partners. We, report solution NMR evidence that ResA undergoes a redox-dependent, conformational change between oxidation states, as well as data showing, that ResA utilizes a surface cavity present only in the reduced state to, recognize a peptide derived from cytochrome c550. Finally, we confirm that, ResA is a specific thiol-disulfide oxidoreductase by comparing its, reactivity to our mimetic peptide with its reactivity to oxidized, glutathione, a nonspecific substrate. This study biochemically, demonstrates the specificity of this thiol-disulfide oxidoreductase and, enables us to outline a structural mechanism of regulating the usage of, electrons in a thiol-disulfide oxidoreductase system.
About this Structure
2F9S is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
Mechanism of substrate specificity in Bacillus subtilis ResA, a thioredoxin-like protein involved in cytochrome c maturation., Colbert CL, Wu Q, Erbel PJ, Gardner KH, Deisenhofer J, Proc Natl Acad Sci U S A. 2006 Mar 21;103(12):4410-5. Epub 2006 Mar 13. PMID:16537372
Page seeded by OCA on Wed Nov 21 10:26:28 2007
