Structure-Function Analysis of the Bifunctional CcsBA Heme Exporter and Cytochrome c Synthetase.

ABSTRACT: Although intracellular heme trafficking must occur for heme protein assembly, only a few heme transporters have been unequivocally discovered and nothing is known about their structure or mechanisms. Cytochrome c biogenesis in prokaryotes requires the transport of heme from inside to outside for stereospecific attachment to cytochrome c via two thioether bonds (at CXXCH). The CcsBA integral membrane protein was shown to transport and attach heme (and thus is a cytochrome c synthetase), but the structure and mechanisms underlying these two activities are poorly understood. We employed a new cysteine/heme crosslinking tool that traps endogenous heme in heme binding sites. We combined these data with a comprehensive imidazole correction approach (for heme ligand interroga

SUBMITTER: Sutherland MC 

PROVIDER: S-EPMC6299221 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature