Affiliation:
1. Korea Polar Research Institute
2. Sun Moon University
Abstract
Abstract
Heavy metals, including mercury, are non-biodegradable and highly toxic to microorganisms even at low concentrations. Understanding the mechanisms underlying the environmental adaptability of microorganisms with Hg resistance holds promise for their use in Hg bioremediation. We characterized GbsMerA, a mercury reductase belonging to the mercury-resistant operon of Gelidibacter salicanalis PAMC21136, and found its specific activity in reducing Hg+2. Its enzyme activity was the highest in the presence of Hg+2 and moderate in the presence of Ag+ and Mn+2. GbsMerA exhibited optimal activity at pH 7.0 and a temperature of 60 °C. GbsMerA contains unique residues, Tyr437´ and Asp47, which are responsible for metal transfer at the si-face. The complex structure with NADPH indicated that Y174 in the re-face is a gate for NADPH binding. This study provides a background for understanding Hg detoxification by GbsMerA and suggests the application of genetically engineered E. coli strains for environmental Hg removal.
Publisher
Research Square Platform LLC
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