Acetate excretion during growth of Salmonella enterica on ethanolamine requires phosphotransacetylase (EutD) activity, and acetate recapture requires acetyl-CoA synthetase (Acs) and phosphotransacetylase (Pta) activities.
This report shows that Salmonella enterica catabolizes ethanolamine to acetyl-CoA (Ac-CoA), which enters the glyoxylate bypass and tricarboxylic acid cycle for the generation of energy and central metabolites. During growth on ethanolamine, S. enterica excreted acetate, whose recapture depended on Ac-CoA synthetase (Acs) and the housekeeping phosphotransacetylase (Pta) enzyme activities. The Pta enzyme did not play a role in acetate excretion during growth of S. enterica on ethanolamine. It is proposed that during growth on ethanolamine, acetate excretion is necessary to maintain a pool of free CoA. Acetate excretion requires the eut operon-encoded phosphotransacetylase (EutD) and acetate kinase (Ack) enzymes. EutD function was not required for growth on ethanolamine, and an eutD strain showed only a slight reduction in growth rate. The existence of an as-yet-unidentified system that releases acetate was revealed during growth of a strain lacking Acs, the housekeeping phosphotransacetylase (Pta), and EutD. The functions of pyruvate oxidase (PoxB), Ack and STM3118 protein [a homologue of the Saccharomyces cerevisiae Ac-CoA hydrolase (Ach1p) enzyme] were not involved in the release of acetate by the acs pta eutD strain.
Starai
Vincent J
VJ
Department of Bacteriology, University of Wisconsin-Madison, 1710 University Ave, Madison, WI 53726-4087, USA.
Garrity
Jane
J
Department of Bacteriology, University of Wisconsin-Madison, 1710 University Ave, Madison, WI 53726-4087, USA.
Escalante-Semerena
Jorge C
JC
Department of Bacteriology, University of Wisconsin-Madison, 1710 University Ave, Madison, WI 53726-4087, USA.
D000106:Acetate-CoA Ligase / Q000378:metabolism*; D000085:Acetates / Q000378:metabolism*; D000105:Acetyl Coenzyme A / Q000378:metabolism; D003470:Culture Media; D019856:Ethanolamine / Q000378:metabolism*; D010709:Phosphate Acetyltransferase / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000201:enzymology / Q000254:growth & development*
D000085:Acetates; D003470:Culture Media; D019856:Ethanolamine; D000105:Acetyl Coenzyme A; D010709:Phosphate Acetyltransferase; D000106:Acetate-CoA Ligase