The auxiliary [4Fe-4S] cluster of the Radical SAM heme synthase from Methanosarcina barkeri is involved in electron transfer.

ABSTRACT: The heme synthase AhbD catalyzes the oxidative decarboxylation of two propionate side chains of iron-coproporphyrin III to the corresponding vinyl groups of heme during the alternative heme biosynthesis pathway occurring in sulfate-reducing bacteria and archaea. AhbD belongs to the family of Radical SAM enzymes and contains two [4Fe-4S] clusters. Whereas one of these clusters is required for substrate radical formation, the role of the second iron-sulfur cluster is not known. In this study, the function of the auxiliary cluster during AhbD catalysis was investigated. Two single cluster variants of AhbD from M. barkeri carrying either one of the two clusters were created. Using these enzyme variants it was shown that the auxiliary cluster is not required for substrate binding and for

SUBMITTER: Kuhner M 

PROVIDER: S-EPMC6013774 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature