The Radical SAM Heme Synthase AhbD from Methanosarcina barkeri Contains Two Auxiliary [4Fe-4S] Clusters.

ABSTRACT: In archaea and sulfate-reducing bacteria, heme is synthesized via the siroheme-dependent pathway. The last step of this route is catalyzed by the Radical SAM enzyme AhbD and consists of the conversion of iron-coproporphyrin III into heme. AhbD belongs to the subfamily of Radical SAM enzymes containing a SPASM/Twitch domain carrying either one or two auxiliary iron-sulfur clusters in addition to the characteristic Radical SAM cluster. In previous studies, AhbD was reported to contain one auxiliary [4Fe-4S] cluster. In this study, the amino acid sequence motifs containing conserved cysteine residues in AhbD proteins from different archaea and sulfate-reducing bacteria were reanalyzed. Amino acid sequence alignments and computational structural models of AhbD suggested that a subset of AhbD p

SUBMITTER: Fix I 

PROVIDER: S-EPMC10452713 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature