Disease relevance of cysM

• Identification of a functional homolog of the Escherichia coli and Salmonella typhimurium cysM gene encoding O-acetylserine sulfhydrylase B in Campylobacter jejuni [1].
• These data indicate that the cloned C. jejuni gene is a functional homolog of the cysM gene that codes for O-acetylserine sulfhydrylase B in E. coli and S. typhimurium [1].

High impact information on cysM

• The results give a gene order of cysA-cysM-crr-ptsl-ptsH-cysK over a distance of approximately 12 kilobases. cysM and cysA have been cloned and expressed in pBR322; attempts to obtain stable pBR322 derivatives carrying cysK were unsuccessful [2].
• The enzyme is identical to cysteine synthase B. The intracellular level of this enzyme was regulated by lesser extents of the same factors as those effective for cysteine synthase A [3].
• Enzymatic proof for the identity of the S-sulfocysteine synthase and cysteine synthase B of Salmonella typhimurium [3].
• The mutant locus responsible for this defect has been designated cysM, and genetic mapping suggests that cysM is very close to and perhaps contiguous with cysA [4].
• Since cysM cysK double mutants are cysteine auxotrophs, by selecting for triazole resistance in cysM strains, mutants arising under this condition also should be constitutive for cysteine biosynthesis [5].

Chemical compound and disease context of cysM

• This paper describes the characterisation of expression of the cysteine biosynthesis genes of Salmonella typhimurium, cysE, cysM and cysK, and linked cysEM, cysME and cysKE genes as transgenes in mice and sheep [6].
• Delayed inducibility of sulphite reductase in cysM mutants of Salmonella typhimurium under anaerobic conditions [7].

Biological context of cysM

• A 4471 bp region between crr and cysM on the Salmonella typhimurium chromosome (49.5 min) has been sequenced [8].
• Nucleotide sequence of the region between crr and cysM in Salmonella typhimurium: five novel ORFs including one encoding a putative transcriptional regulator of the phosphotransferase system [8].

Associations of cysM with chemical compounds

• No difference in the induction of two cysteine biosynthetic enzymes--sulphite reductase and O-acetyl-L-serine sulphydrylase--in wild-type, cysK and cysM strains was observed under aerobic conditions [7].
• These observations are consistent with the assumption that the observed growth delay of the cysM mutant under anaerobic conditions is the result of abnormalities in the regulation of sulphite reductase [7].
• Mutants lacking cysteine synthase B were unable to grow on thiosulfate, whereas mutants lacking cysteine synthase A grew on the four inorganic sulfur sources described above with little difference in their growth rates [9].
• Purification of cysteine synthase B resulted in the copurification of S-sulfocysteine synthase [9].

Other interactions of cysM

• These activities appear to be associated with the cysM gene, and this is able to be cotransducted with the cysK gene at a high frequency [9].

References