Bacterial reduction in Hg(2+) to Hg(0) , mediated by the mercuric reductase (MerA), is important in the biogeochemical cycling of Hg in temperate environments. Little is known about the occurrence and diversity of merA in the Arctic. Seven merA determinants were identified among bacterial isolates from High Arctic snow, freshwater and sea-ice brine. Three determinants in Bacteriodetes, Firmicut...

Mercuric ion reductase (MerA), a mercury detoxification enzyme, has been tuned by evolution to have high specificity for mercuric ions (Hg(2+)) and to catalyze their reduction to a more volatile, less toxic elemental form. Here, we present a biochemical and structural characterization of MerA from the thermophilic crenarchaeon Metallosphaera sedula. MerA from M. sedula is a thermostable enzyme,...

Mercury resistance mediated by mercuric reductase (MerA) is widespread among bacteria and operates under the control of MerR. MerR represents a unique class of transcription factors that exert both positive and negative regulation on gene expression. Archaea and bacteria are prokaryotes, yet little is known about the biological role of mercury in archaea or whether a resistance mechanism occurs...

In a continuing effort to analyze the selectivity/redundancy of the three glutaredoxin (Grx) enzymes of the model cyanobacterium Synechocystis PCC6803, we have characterized an enzyme system that plays a crucial role in protection against two toxic metal pollutants, mercury and uranium. The present data show that Grx1 (Slr1562 in CyanoBase) selectively interacts with the presumptive mercuric re...

The relationship of merA gene expression (specifying the enzyme mercuric reductase) to mercury volatilization in aquatic microbial communities was investigated with samples collected at a mercury-contaminated freshwater pond, Reality Lake, in Oak Ridge, Tenn. Levels of merA mRNA transcripts and the rate of inorganic mercury [Hg(II)] volatilization were related to the concentration of mercury in...

BACKGROUND Many seriously ill and frail inpatients receive potentially inappropriate or harmful medications and do not receive medications for symptoms of advanced illness. We developed and piloted an interprofessional Medication Rationalization (MERA) approach to deprescribing inappropriate medications and prescribing appropriate comfort medications. METHODS We conducted a single-centre pilo...