Identification of proteins capable of metal reduction from the proteome of the Gram-positive bacterium Desulfotomaculum reducens MI-1 using an NADH-based activity assay.

ABSTRACT: Understanding of microbial metal reduction is based almost solely on studies of Gram-negative organisms. In this study, we focus on Desulfotomaculum reducens MI-1, a Gram-positive metal reducer whose genome lacks genes with similarity to any characterized metal reductase. Using non-denaturing separations and mass spectrometry identification, in combination with a colorimetric screen for chelated Fe(III)-NTA reduction with NADH as electron donor, we have identified proteins from the D. reducens proteome not previously characterized as iron reductases. Their function was confirmed by heterologous expression in Escherichia coli. Furthermore, we show that these proteins have the capability to reduce soluble Cr(VI) and U(VI) with NADH as electron donor. The proteins identified are NADH : flavin

SUBMITTER: Otwell AE 

PROVIDER: S-EPMC4474781 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature