title: Mutations in sdh (succinate dehydrogenase genes) alter the thiamine requirement of Salmonella typhimurium.
abstract: Mutants lacking the first enzyme in de novo purine synthesis (PurF) can synthesize thiamine if increased levels of pantothenate are present in the culture medium (J. L. Enos-Berlage and D. M. Downs, J. Bacteriol. 178:1476-1479, 1996). Derivatives of purF mutants that no longer required pantothenate for thiamine-independent growth were isolated. Analysis of these mutants demonstrated that they were defective in succinate dehydrogenase (Sdh), an enzyme of the tricarboxylic acid cycle. Results of phenotypic analyses suggested that a defect in Sdh decreased the thiamine requirement of Salmonella typhimurium. This reduced requirement correlated with levels of succinyl-coenzyme A (succinyl-CoA), which is synthesized in a thiamine pyrophosphate-dependent reaction. The effect of succinyl-CoA on thiamine metabolism was distinct from the role of pantothenate in thiamine synthesis.
authors.affiliation: Department of Bacteriology, University of Wisconsin-Madison, 53706, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Enos-Berlage
authors.forename: D M
authors.initials: DM
authors.lastname: Downs
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism; D009154:Mutation; D010205:Pantothenic Acid / Q000502:physiology; D012486:Salmonella typhimurium / Q000378:metabolism*; D013385:Succinate Dehydrogenase / Q000235:genetics / Q000502:physiology*; D013386:Succinates / Q000494:pharmacology; D019802:Succinic Acid; D013831:Thiamine / Q000096:biosynthesis*
chemical_list: D000214:Acyl Coenzyme A; D013386:Succinates; D010205:Pantothenic Acid; D019802:Succinic Acid; C012046:succinyl-coenzyme A; D013385:Succinate Dehydrogenase; D013831:Thiamine