Inhibition of fructose-1,6-bisphosphatase by aminoimidazole carboxamide ribotide prevents growth of Salmonella enterica purH mutants on glycerol.
The enzyme fructose-1,6-bisphosphatase (FBP) is key regulatory point in gluconeogenesis. Mutants of Salmonella enterica lacking purH accumulate 5-amino-4-imidazole carboxamide ribotide (AICAR) and are unable to utilize glycerol as sole carbon and energy sources. The work described here demonstrates this lack of growth is due to inhibition of FBP by AICAR. Mutant alleles of fbp that restore growth on glycerol encode proteins resistant to inhibition by AICAR and the allosteric regulator AMP. This is the first report of biochemical characterization of substitutions causing AMP resistance in a bacterial FBP. Inhibition of FBP activity by AICAR occurs at physiologically relevant concentrations and may represent a form of regulation of gluconeogenic flux in Salmonella enterica.
Dougherty
Michael J
MJ
Department of Bacteriology, University of Wisconsin, Madison, Wisconsin 53706, USA.
Boyd
Jeffrey M
JM
Downs
Diana M
DM
D000249:Adenosine Monophosphate / Q000494:pharmacology; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D005632:Fructose / Q000378:metabolism; D006597:Fructose-Bisphosphatase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D012265:Ribonucleotides / Q000494:pharmacology*; D019779:Salmonella enterica / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development*; D017386:Sequence Homology, Amino Acid
D007004:Hypoglycemic Agents; D012265:Ribonucleotides; D005632:Fructose; D000620:Aminoimidazole Carboxamide; D000249:Adenosine Monophosphate; D006597:Fructose-Bisphosphatase; C031143:AICA ribonucleotide; D005990:Glycerol