Disease relevance of hisG

• Relief of transcriptional polarity by a mutation that creates a promoter in the hisG gene of Salmonella typhimurium LT2 [1].

High impact information on hisG

• Deletion revertants are identified in a simple phenotypic screen by their resistance to the inhibitory histidine analog thiazolealanine, which feedback inhibits the wild-type hisG enzyme but not the enzyme resulting from the deletions [2].
• It was complemented by DNA sequence analysis (done in another laboratory) of the hisG gene, which codes for it [3].
• Amino acid sequence of ATP phosphoribosyltransferase of Salmonella typhimurium [3].
• Regulation of histidine operon does not require hisG enzyme [4].
• Diol-epoxide-induced cytotoxicity and mutation frequencies at the hisG and gpt loci were determined [5].

Chemical compound and disease context of hisG

• Mutations are described which delete all or part of the first structural gene (hisG) of the histidine operon of Salmonella typhimurium [4].
• Histidine mutants requiring adenine: selection of mutants with reduced hisG expression in Salmonella typhimurium [6].

Biological context of hisG

• DNA sequence analysis showed that all six mutants result from the same nucleotide alteration: a G/C to A/T transition 4 bp from the end of the hisG coding sequence [1].
• Constitutive high operon expression is observed in strains carrying any hisG deletion and an unlinked regulatory mutation, hisT1504 [4].
• URA3 selection was used repeatedly for the sequential introduction of mutations by flanking the URA3 gene with direct repeats of the Salmonella typhimurium hisG gene [7].
• Nonsense and insertion mutations mapping upstream of this point in the hisG gene all have strong polar effects on expression of downstream genes in the operon; mutations mapping promotor distal to this site have little or no polar effect [8].
• The intracellular concentrations of the enzymes encoded in the histidine operon in a strain carrying such a mutation on an episome and missing the chromosomal hisG gene are three- to fourfold higher than in a strain carrying a wild-type hisG gene on the episome [9].

Associations of hisG with chemical compounds

• Some revertant clones that no longer require adenine contain mutations in hisG, hisE, or the his-control region [6].
• Rare revertants of hisD497 are deletions fusing the hisD gene to the adjacent preceding structural gene, hisG (adenosine 5'-triphosphate-PR transferase) [10].
• Synergistic inhibition of ATP phosphoribosyltransferase by guanosine tetraphosphate and histidine [11].
• However, unlike the ATP phosphoribosyltransferase coded by the hisG46 his G gene (with a proline), the arginine mutant enzyme is partially active [12].

Other interactions of hisG

• Transduction studies demonstrated that mutations of his+ were closely linked to the hisD gene, and probably were in the structural hisG gene itself [13].

References