This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Downs, D M Search for Related Content PubMed PubMed Citation Articles by Downs, D M

research-article

Evidence for a new, oxygen-regulated biosynthetic pathway for the pyrimidine moiety of thiamine in Salmonella typhimurium.

Department of Bacteriology, University of Wisconsin, Madison 53706.

ABSTRACT

The synthesis of the pyrimidine moiety of thiamine (vitamin B1) shares five reactions with the de novo purine biosynthetic pathway. Aminoimidazole ribotide (AIR) is the last common intermediate before the two pathways diverge. Evidence for the existence of a new pathway to the pyrimidine which bypasses the de novo purine biosynthetic pathway is reported here. This pathway is only expressed under anaerobic growth conditions and is denoted alternative pyrimidine biosynthesis or APB. Labeling studies are consistent with pantothenate being a precursor to the pyrimidine moiety of thiamine that is synthesized by the APB pathway. The APB pathway is independent of the alternative purF function which was proposed previously (D. M. Downs and J. R. Roth, J. Bacteriol. 173:6597-6604, 1991). The alternative purF function is shown here to be affected by temperature and exogenous pantothenate. Although the evidence suggests that the APB pathway is separate from the alternative purF function, the relationship between this function and the APB pathway is not yet clear.

This article has been cited by other articles:

• Gralnick, J. A., Downs, D. M. (2003). The YggX Protein of Salmonella enterica Is Involved in Fe(II) Trafficking and Minimizes the DNA Damage Caused by Hydroxyl Radicals: RESIDUE CYS-7 IS ESSENTIAL FOR YggX FUNCTION. J. Biol. Chem. 278: 20708-20715 [Abstract] [Full Text]  
• Bjork, G. R., Nilsson, K. (2003). 1-Methylguanosine-Deficient tRNA of Salmonella enterica Serovar Typhimurium Affects Thiamine Metabolism. J. Bacteriol. 185: 750-759 [Abstract] [Full Text]  
• Gralnick, J., Downs, D. (2001). Protection from superoxide damage associated with an increased level of the YggX protein in Salmonellla enterica. Proc. Natl. Acad. Sci. USA 10.1073/pnas.151243198v1 [Abstract] [Full Text]  
• Gralnick, J., Webb, E., Beck, B., Downs, D. (2000). Lesions in gshA (Encoding gamma -L-Glutamyl-L-Cysteine Synthetase) Prevent Aerobic Synthesis of Thiamine in Salmonella enterica Serovar Typhimurium LT2. J. Bacteriol. 182: 5180-5187 [Abstract] [Full Text]  
• Claas, K., Weber, S., Downs, D. M. (2000). Lesions in the nuo Operon, Encoding NADH Dehydrogenase Complex I, Prevent PurF-Independent Thiamine Synthesis and Reduce Flux through the Oxidative Pentose Phosphate Pathway in Salmonella enterica Serovar Typhimurium. J. Bacteriol. 182: 228-232 [Abstract] [Full Text]  
• Frodyma, M., Rubio, A., Downs, D. M. (2000). Reduced Flux through the Purine Biosynthetic Pathway Results in an Increased Requirement for Coenzyme A in Thiamine Synthesis in Salmonella enterica Serovar Typhimurium. J. Bacteriol. 182: 236-240 [Abstract] [Full Text]  
• Enos-Berlage, J. L., Downs, D. M. (1999). Biosynthesis of the Pyrimidine Moiety of Thiamine Independent of the PurF Enzyme (Phosphoribosylpyrophosphate Amidotransferase) in Salmonella typhimurium: Incorporation of Stable Isotope-Labeled Glycine and Formate. J. Bacteriol. 181: 841-848 [Abstract] [Full Text]  
• Enos-Berlage, J. L., Langendorf, M. J., Downs, D. M. (1998). Complex Metabolic Phenotypes Caused by a Mutation in yjgF, Encoding a Member of the Highly Conserved YER057c/YjgF Family of Proteins. J. Bacteriol. 180: 6519-6528 [Abstract] [Full Text]  
• Frodyma, M. E., Downs, D. (1998). The panE Gene, Encoding Ketopantoate Reductase, Maps at 10 Minutes and Is Allelic to apbA in Salmonella typhimurium. J. Bacteriol. 180: 4757-4759 [Abstract] [Full Text]  
• Frodyma, M. E., Downs, D. (1998). ApbA, the Ketopantoate Reductase Enzyme of Salmonella typhimurium Is Required for the Synthesis of Thiamine via the Alternative Pyrimidine Biosynthetic Pathway. J. Biol. Chem. 273: 5572-5576 [Abstract] [Full Text]  
• Beck, B. J., Downs, D. M. (1998). The apbE Gene Encodes a Lipoprotein Involved in Thiamine Synthesis in Salmonella typhimurium. J. Bacteriol. 180: 885-891 [Abstract] [Full Text]  
• Gralnick, J., Downs, D. (2001). Protection from superoxide damage associated with an increased level of the YggX protein in Salmonella enterica. Proc. Natl. Acad. Sci. USA 98: 8030-8035 [Abstract] [Full Text]