Arsenic and selenium in microbial metabolism.
Arsenic and selenium are readily metabolized by prokaryotes, participating in a full range of metabolic functions including assimilation, methylation, detoxification, and anaerobic respiration. Arsenic speciation and mobility is affected by microbes through oxidation/reduction reactions as part of resistance and respiratory processes. A robust arsenic cycle has been demonstrated in diverse environments. Respiratory arsenate reductases, arsenic methyltransferases, and new components in arsenic resistance have been recently described. The requirement for selenium stems primarily from its incorporation into selenocysteine and its function in selenoenzymes. Selenium oxyanions can serve as an electron acceptor in anaerobic respiration, forming distinct nanoparticles of elemental selenium that may be enriched in (76)Se. The biogenesis of selenoproteins has been elucidated, and selenium methyltransferases and a respiratory selenate reductase have also been described. This review highlights recent advances in ecology, biochemistry, and molecular biology and provides a prelude to the impact of genomics studies.
Stolz
John F
JF
Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282, USA. stolz@duq.edu
Basu
Partha
P
Santini
Joanne M
JM
Oremland
Ronald S
RS
D000595:Amino Acid Sequence; D053502:Arsenate Reductases / Q000502:physiology; D001151:Arsenic / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D004351:Drug Resistance; D004463:Ecology; D008745:Methylation; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000502:physiology; D010802:Phylogeny; D012643:Selenium / Q000378:metabolism*; D017279:Selenocysteine / Q000378:metabolism
D017279:Selenocysteine; D010088:Oxidoreductases; C078179:arsenite oxidase; D053502:Arsenate Reductases; C078108:selenate reductase; D012643:Selenium; D001151:Arsenic