Bacterial detoxification of Hg(II) and organomercurials

Essays Biochem. 1999:34:17-30. doi: 10.1042/bse0340017.

Abstract

The most common bacterial mechanism for resistance to mercuric-ion species involves intracellular reduction of Hg(II) to Hg(0). Key proteins of the pathway typically include: MerR, which regulates pathway expression; MerP, which protects the external environment; MerT or MerC, which transport Hg(II) species across the inner membrane; MerA, which catalyses reduction of Hg(II); and sometimes MerB, which catalyses cleavage of C-Hg bonds in organomercurials. Cysteine residues of varying number are arranged in each of the key proteins to optimize their unique roles in sensing (high affinity), transporting (exchangeability), and reducing (redox accessibility) Hg(II). Nature's regulator of this pathway, MerR, is an exquisitely sensitive, Hg(II)-binding, DNA-binding protein that holds the system primed for immediate transcription at the slightest influx of Hg(II).

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Bacteria / genetics
  • Bacteria / metabolism*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Drug Resistance, Microbial
  • Gene Expression Regulation, Bacterial
  • Inactivation, Metabolic
  • Mercury / metabolism*
  • Models, Molecular
  • Operon
  • Organomercury Compounds / metabolism*

Substances

  • Bacterial Proteins
  • Carrier Proteins
  • Organomercury Compounds
  • Mercury