Disease relevance of arsC

• Full-length arsenate reductase without any modification has been expressed in Escherichia coli and purified in a soluble form [1].
• Preparation and crystallization of a Bacillus subtilis arsenate reductase [1].
• The structure of a triple mutant of pI258 arsenate reductase from Staphylococcus aureus and its 5-thio-2-nitrobenzoic acid adduct [2].

High impact information on arsC

• ArsC has now been shown to be an arsenate reductase, converting intracellular arsenate [As(V)] to arsenite [As(III)], which is then exported from the cells by an energy-dependent efflux process [3].
• The arsenate reductase activity was found in the soluble cytoplasmic fraction in Escherichia coli (and not associated with the periplasmic fraction or the sedimentable cell envelope) [3].
• Finally, the less well documented arsenate reductase activity of the monomeric arsenic(III) methylase, which is an S-adenosylmethionine (AdoMet)-dependent methyltransferase [4].
• In contrast, the ArrAB complex is a bacterial heterodimeric periplasmic or a surface-anchored arsenate reductase that functions as a terminal electron acceptor and transfers electrons from the membrane respiratory chain to arsenate [4].
• PV4-8 expression improved arsenate resistance in E. coli WC3110, a strain deficient in arsenate reductase but not in AW3110 deficient for the whole ars operon [5].

Biological context of arsC

• This chromosomal operon was cloned, sequenced, and found to consist of three cistrons which we named arsR, arsB, and arsC because of their strong homology to plasmid-borne ars operons [6].
• The rice genome contains two ACR2-like genes, OsACR2.1 and OsACR2.2, which may be involved in regulating arsenic metabolism in rice. * Here, we cloned both OsACR2 genes and expressed them in an Escherichia coli strain in which the arsC gene was deleted and in a yeast (Saccharomyces cerevisiae) strain with a disrupted ACR2 gene [7].
• 2. Mutagenesis of cysteine residues in the putative active site HC(X)(5)R motif led to nearly complete loss of both phosphatase and arsenate reductase activities. * In planta expression of OsACR2.1 increased dramatically after exposure to arsenate [7].

Associations of arsC with chemical compounds

• Induced At. caldus also expressed arsenate reductase activity, indicating that At. caldus has an arsenical resistance mechanism that is analogous to previously described systems from other Bacteria [8].
• This structural arrangement shows similarities with other IIB subunits but also with mammalian low molecular weight protein tyrosine phosphatases (LMW PTPase) and arsenate reductase (ArsC) [9].

Other interactions of arsC

• The chromosomal At. caldus ars genes were cloned and found to consist of arsR and arsC genes transcribed in one direction, and arsB in the opposite direction [10].

References