CcmG is unlike other periplasmic thioredoxin (TRX)-like proteins in that it has a specific reducing activity in an oxidizing environment and a high fidelity of interaction. These two unusual properties are required for its role in c-type cytochrome maturation ...
CcmG is unlike other periplasmic thioredoxin (TRX)-like proteins in that it has a specific reducing activity in an oxidizing environment and a high fidelity of interaction. These two unusual properties are required for its role in c-type cytochrome maturation. The crystal structure of CcmG reveals a modified TRX fold with an unusually acidic active site and a groove formed from two inserts in the fold. Deletion of one of the groove-forming inserts disrupts c-type cytochrome formation. Two unique structural features of CcmG-an acidic active site and an adjacent groove-appear to be necessary to convert an indiscriminately binding scaffold, the TRX fold, into a highly specific redox protein.
Related Citations:
Crystallization and preliminary diffraction studies of native and selenomethionine CcmG (CycY, DsbE) Edeling, M.A., Guddat, L.W., Fabianek, R.A., Halliday, J.A., Jones, A., Thony-Meyer, L., Martin, J.L. (2001) Acta Crystallogr D Biol Crystallogr 57: 1293
Characterization of the Bradyrhizobium japonicum CycY protein, a membrane-anchored periplasmic thioredoxin that may play a role as a reductant in the biogenesis of c-type cytochromes Fabianek, R.A., Huber-Wunderlich, M., Glockshuber, R., Kunzler, P., Hennecke, H., Thony-Meyer, L. (1997) J Biol Chem 272: 4467
The active-site cysteines of the periplasmic thioredoxin-like protein CcmG of Escherichia coli are important but not essential for cytochrome c maturation in vivo. Fabianek, R.A., Hennecke, H., Thony-Meyer, L. (1998) J Bacteriol 180: 1947
Organizational Affiliation:
Centre for Drug Design and Development and Special Research Centre for Functional and Applied Genomics, Institute for Molecular Bioscience, Brisbane QLD 4072, Australia.
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