2f9s
2nd Crystal Structure Of A Soluble Domain Of ResA In The Oxidised Form
Structural highlights
FunctionRESA_BACSU Thiol-disulfide oxidoreductase which is required in disulfide reduction during c-type cytochrome synthesis. May accept reducing equivalents from CcdA, leading to breakage of disulfide bonds in apocytochrome c; following this reduction heme can be covalently attached. Does not play a role in sporulation.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. 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[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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