Effect of replacing the general energy-coupling proteins of the PEP:sugar phosphotransferase system of Salmonella typhimurium with their fructose-inducible counterparts on utilization of the PTS sugar glucitol.
A strain of Salmonella typhimurium in which the genes encoding the general phosphoenolpyruvate:sugar phosphotransferase system (PTS) proteins HPr and Enzyme I have been deleted, the normally cryptic gene encoding the fructose-inducible Enzyme I (EI* or EI(fructose)) is expressed, and the fructose repressor protein is inactive (fruR or cra mutant) was studied. This strain lacks HPr and EI, but expresses FPr (DTP) and EI(fructose) constitutively. Since FPr and EI(fructose) can substitute for HPr and EI, the strain grew in minimal liquid medium supplemented with the PTS sugars glucose, fructose, N-acetylglucosamine, mannitol or mannose. However, it showed very poor to negligible growth on the PTS sugar glucitol. It also grew very poorly on the non-PTS sugars maltose, melibiose and especially glycerol. Adding cAMP to the medium allowed growth on glucitol, but did not affect growth on glycerol. We suggest that poor phosphorylation of the regulatory molecule Enzyme IIA(glucose) by FPr is responsible for these effects.
Sutrina
Sarah L
SL
Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus, Barbados1.
Alleyne
Lisa
L
Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus, Barbados1.
Hoyte
Keisher
K
Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus, Barbados1.
Blenman
Margot
M
Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus, Barbados1.
D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D000242:Cyclic AMP / Q000378:metabolism; D029968:Escherichia coli Proteins; D005632:Fructose / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D047908:Intracellular Signaling Peptides and Proteins; D009154:Mutation; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics / Q000378:metabolism*; D017852:Phosphotransferases (Nitrogenous Group Acceptor) / Q000235:genetics / Q000378:metabolism; D012486:Salmonella typhimurium / Q000201:enzymology / Q000254:growth & development*; D013012:Sorbitol / Q000378:metabolism*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D003470:Culture Media; D029968:Escherichia coli Proteins; D047908:Intracellular Signaling Peptides and Proteins; C032242:crr protein, E coli; C028640:fructose-induced HPr-like protein, bacteria; D005632:Fructose; D013012:Sorbitol; D000242:Cyclic AMP; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C030182:phosphocarrier protein HPr; D017852:Phosphotransferases (Nitrogenous Group Acceptor); C022360:phosphoenolpyruvate-protein phosphotransferase