Purification and characterization of a soluble cytochrome c capable of delivering electrons to chlorate reductase in Ideonella dechloratans.

The electron donor for periplasmic chlorate reductase of Ideonella dechloratans has been suggested to be a soluble cytochrome c. We describe here the purification of the 9-kDa periplasmic cytochrome c, denoted cytochrome c-Id1, and demonstrate its ability to serve as an electron donor for purified chlorate reductase. The reaction rate was found to be linearly dependent on the cytochrome c concentration in the range of 0.6-4 μM. A route for electron transport involving a soluble cytochrome c is similar to that found for other periplasmic oxidoreductases of the dimethyl sulfoxide reductase family, but different from that suggested for the (per)chlorate reductase of Dechloromonas species. 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.