ISSN:
1432-072X
Keywords:
Energetics (of glucose uptake)
;
Growth yield
;
Salmonella typhimurium
;
Uncoupled enzyme IIGlc
;
Glucose phosphotransferase system
;
Glucose transport
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Uncoupled enzyme IIGlc of the phosphoenolpyruvate (PEP): glucose phosphotransferase system (PTS) in Salmonella typhimurium is able to catalyze glucose transport in the absence of PEP-dependent phosphorylation. We have studied the energetics of glucose uptake catalyzed by this uncoupled enzyme IIGlc. The molar growth yields on glucose of two strains cultured anaerobically in glucose-limited chemostat-and batch cultures were compared. Strain PP 799 transported and phosphorylated glucose via an intact PTS, while strain PP 952 took up glucose exclusively via uncoupled enzyme IIGlc, followed by ATP-dependent phosphorylation by glucokinase. Thus the strains were isogenic except for the mode of uptake and phosphorylation of the growth substrate. PP 799 and PP 952 exhibited similar Y Glc values. Assuming equal Y ATP values for both strains this result indicated that there were no energetic demands for glucose uptake via uncoupled enzyme IIGlc.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00252206
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