RT Journal Article SR Electronic(1) A1 Larossa, Robert A. A1 Van Dyk, Tina K.YR 1989 T1 Leaky Pantothenate and Thiamin Mutations of Salmonella typhimurium Conferring Sulphometuron Methyl Sensitivity JF Microbiology, VO 135 IS 8 SP 2209 OP 2222 DO https://doi.org/10.1099/00221287-135-8-2209 PB Microbiology Society, SN 1465-2080, AB The herbicide suphometuron methyl inhibits the utilization of pyruvate and 2-ketobutyrate by the branched-chain amino acid biosynthetic enzyme acetolactate synthase. Eighteen insertions of the transposon Tn10 into the genome of Salmonella typhimurium LT2 caused hypersensitivity to this herbicide. Five of these insertions conferred a partial auxotrophic requirement. Concurrent herbicide sensitivity and heat-labile pantothenate auxotrophy was due to panD::Tn10 mutations, while coincident sulphometuron methyl sensitivity and thiamin auxotrophy was attributable to thiA::Tn10 mutations. The phenotypes of these mutations suggested that coenzyme A and thiamin pyrophosphate availability modulated the cells’ response to sulphometuron methyl. A model suggesting a key role for 2-ketobutyrate accumulation in herbicide action is supported by the function of thiamin pyrophosphate in 2-ketoacid metabolism and the known role of a 2-ketoacid in coenzyme A synthesis., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-135-8-2209