Molecular Adaptations of Bacterial Mercuric Reductase to the Hypersaline Kebrit Deep in the Red Sea.

ABSTRACT: The hypersaline Kebrit Deep brine pool in the Red Sea is characterized by high levels of toxic heavy metals. Here, we describe two structurally related mercuric reductases (MerAs) from this site which were expressed in Escherichia coli Sequence similarities suggest that both genes are derived from proteobacteria, most likely the Betaproteobacteria or Gammaproteobacteria We show that one of the enzymes (K35NH) is strongly inhibited by NaCl, while the other (K09H) is activated in a NaCl-dependent manner. We infer from this difference that the two forms might support the detoxification of mercury in bacterial microorganisms that employ the compatible solutes and salt-in strategies, respectively. Three-dimensional structure modeling shows that all amino acid substitutions

SUBMITTER: Ramadan E 

PROVIDER: S-EPMC6365835 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature