Structural insights into dissimilatory sulfite reductases: structure of desulforubidin from desulfomicrobium norvegicum.

ABSTRACT: Dissimilatory sulfite reductases (dSiRs) are crucial enzymes in bacterial sulfur-based energy metabolism, which are likely to have been present in some of the earliest life forms on Earth. Several classes of dSiRs have been proposed on the basis of different biochemical and spectroscopic properties, but it is not clear whether this corresponds to actual physiological or structural differences. Here, we describe the first structure of a dSiR from the desulforubidin class isolated from Desulfomicrobium norvegicum. The desulforubidin (Drub) structure is assembled as α(2)β(2)γ(2), in which two DsrC proteins are bound to the core [DsrA](2)[DsrB](2) unit, as reported for the desulfoviridin (Dvir) structure from Desulfovibrio vulgaris. Unlike Dvir, four sirohemes and eight [4Fe-4S] clusters are p

SUBMITTER: Oliveira TF 

PROVIDER: S-EPMC3153041 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature