Visualizing changes in electron distribution in coupled chains of cytochrome bc(1) by modifying barrier for electron transfer between the FeS cluster and heme c(1).

ABSTRACT: Cytochrome c(1) of Rhodobacter (Rba.) species provides a series of mutants which change barriers for electron transfer through the cofactor chains of cytochrome bc(1) by modifying heme c(1) redox midpoint potential. Analysis of post-flash electron distribution in such systems can provide useful information about the contribution of individual reactions to the overall electron flow. In Rba. capsulatus, the non-functional low-potential forms of cytochrome c(1) which are devoid of the disulfide bond naturally present in this protein revert spontaneously by introducing a second-site suppression (mutation A181T) that brings the potential of heme c(1) back to the functionally high levels, yet maintains it some 100 mV lower from the native value. Here we report that the disulfide and the mutation

SUBMITTER: Cieluch E 

PROVIDER: S-EPMC2807467 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature