title: Cloning and physical mapping of the cysB region of Salmonella typhimurium.
abstract: The cysB region of Salmonella typhimurium was cloned in pBR322 and localized to a 1.75-kilobase HincII fragment. Two-dimensional protein electropherograms showed levels of the cysB polypeptide chain that were several fold higher in plasmid-bearing strains than in the wild type. Fully derepressed levels of sulfite reductase and O-acetylserine sulfhydrylase in cysB plasmid-bearing strains were only 25% higher than in the wild type, suggesting that the product of this regulatory gene ordinarily is not a limiting factor in the expression of the cysteine regulon. The mapping of cysB deletions by Southern blots showed a good correlation between the genetic and the physical maps of this gene. The supX gene was initially cloned with cysB and is within 0.7 kilobase of cysB.
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D003001:Cloning, Molecular; D003545:Cysteine / Q000235:genetics*; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial / Q000032:analysis; D005798:Genes, Bacterial; D010957:Plasmids; D012486:Salmonella typhimurium / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004262:DNA Restriction Enzymes; D003545:Cysteine