Crystal structure of Adenylylsulfate reductase from Desulfovibrio gigas suggests a potential self-regulation mechanism involving the C terminus of the beta-subunit.

ABSTRACT: Adenylylsulfate reductase (adenosine 5'-phosphosulfate [APS] reductase [APSR]) plays a key role in catalyzing APS to sulfite in dissimilatory sulfate reduction. Here, we report the crystal structure of APSR from Desulfovibrio gigas at 3.1-A resolution. Different from the alpha(2)beta(2)-heterotetramer of the Archaeoglobus fulgidus, the overall structure of APSR from D. gigas comprises six alphabeta-heterodimers that form a hexameric structure. The flavin adenine dinucleotide is noncovalently attached to the alpha-subunit, and two [4Fe-4S] clusters are enveloped by cluster-binding motifs. The substrate-binding channel in D. gigas is wider than that in A. fulgidus because of shifts in the loop (amino acid 326 to 332) and the alpha-helix (amino acid 289 to 299) in the alpha-subunit. The posit

SUBMITTER: Chiang YL 

PROVIDER: S-EPMC2786610 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature