title: Cloning of mycobacterial histidine synthesis genes by complementation of a Mycobacterium smegmatis auxotroph.
abstract: Histidine-requiring auxotrophs of Mycobacterium smegmatis were isolated following N-methyl-N'-nitro-N-nitrosoguanidine treatment. One of these mutants, his5, was transformed with an M. smegmatis shuttle cosmid library, and complementing clones were isolated at a frequency of approximately 1%. A 2.3 kb fragment was subcloned and sequenced, and found to contain the start of an operon including the hisD gene and part of the hisC gene. No hisG gene was detected upstream of hisD, suggesting that the regulation of histidine biosynthesis in mycobacteria may differ from that of Escherichia coli. The strategy used here will allow the molecular genetics of complex mycobacterial-specific biosynthetic pathways involved in the virulence of pathogenic species to be studied.
authors.affiliation: Department of Clinical Sciences, London School of Hygiene and Tropical Medicine, UK.
authors.forename: S
authors.initials: S
authors.lastname: Hinshelwood
authors.forename: N G
authors.initials: NG
authors.lastname: Stoker
mesh_terms: D001276:ATP Phosphoribosyltransferase / Q000235:genetics; D000429:Alcohol Oxidoreductases; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D006639:Histidine / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D009161:Mycobacterium / Q000235:genetics* / Q000378:metabolism; D009876:Operon; D000637:Transaminases / Q000737:chemistry / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D006639:Histidine; D000429:Alcohol Oxidoreductases; C021358:histidinol dehydrogenase; D001276:ATP Phosphoribosyltransferase; D000637:Transaminases; C053430:histidinol-phosphate aminotransferase