Download MendeleyStructural Basis of Redox-coupled Protein Substrate Selection by the Cytochrome c Biosynthesis Protein ResA.
Crow, A., Acheson, R.M., Le Brun, N.E., Oubrie, A.(2004) J Biol Chem 279: 23654-23660
- PubMed: 15047692
- DOI: https://doi.org/10.1074/jbc.M402823200
- Primary Citation of Related Structures:
1ST9, 1SU9 - PubMed Abstract:
Post-translational maturation of cytochromes c involves the covalent attachment of heme to the Cys-Xxx-Xxx-Cys-His motif of the apo-cytochrome. For this process, the two cysteines of the motif must be in the reduced state. In bacteria, this is achieved by dedicated, membrane-bound thiol-disulfide oxidoreductases with a high reducing power, which are essential components of cytochrome c maturation systems and are also linked to cellular disulfide-bond formation machineries. Here we report high-resolution structures of oxidized and reduced states of a soluble, functional domain of one such oxidoreductase, ResA, from Bacillus subtilis. The structures elucidate the structural basis of the protein's high reducing power and reveal the largest redox-coupled conformational changes observed to date in any thioredoxin-like protein. These redox-coupled changes alter the protein surface and illustrate how the redox state of ResA predetermines to which substrate it binds. Furthermore, a polar cavity, present only in the reduced state, may confer specificity to recognize apo-cytochrome c. The described features of ResA are likely to be general for bacterial cytochrome c maturation systems.
Organizational Affiliation:
School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom.
