Arsenic detoxification and evolution of trimethylarsine gas by a microbial arsenite S-adenosylmethionine methyltransferase

Proc Natl Acad Sci U S A. 2006 Feb 14;103(7):2075-80. doi: 10.1073/pnas.0506836103. Epub 2006 Feb 1.

Abstract

In this article, a mechanism of arsenite [As(III)]resistance through methylation and subsequent volatization is described. Heterologous expression of arsM from Rhodopseudomonas palustris was shown to confer As(III) resistance to an arsenic-sensitive strain of Escherichia coli. ArsM catalyzes the formation of a number of methylated intermediates from As(III), with trimethylarsine as the end product. The net result is loss of arsenic, from both the medium and the cells. Because ArsM homologues are widespread in nature, this microbial-mediated transformation is proposed to have an important impact on the global arsenic cycle.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arsenic / metabolism*
  • Arsenic / pharmacology
  • Arsenicals / metabolism*
  • Arsenites / metabolism
  • Cloning, Molecular
  • Drug Resistance / genetics
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology
  • Escherichia coli / genetics
  • Gene Expression Regulation, Bacterial
  • Inactivation, Metabolic
  • Methylation
  • Methyltransferases / chemistry
  • Methyltransferases / genetics
  • Methyltransferases / metabolism*
  • Rhodopseudomonas / enzymology*
  • Rhodopseudomonas / genetics
  • S-Adenosylmethionine / metabolism
  • Transcription, Genetic
  • Volatilization

Substances

  • Arsenicals
  • Arsenites
  • S-Adenosylmethionine
  • Methyltransferases
  • trimethylarsine
  • arsenite
  • Arsenic