Regulation of glycerol uptake by the phosphoenolpyruvate-sugar phosphotransferase system in Bacillus subtilis.

AUTOR(ES)

Reizer, J

RESUMO

Enteric bacteria have been previously shown to regulate the uptake of certain carbohydrates (lactose, maltose, and glycerol) by an allosteric mechanism involving the catalytic activities of the phosphoenolpyruvate-sugar phosphotransferase system. In the present studies, a ptsI mutant of Bacillus subtilis, possessing a thermosensitive enzyme I of the phosphotransferase system, was used to gain evidence for a similar regulatory mechanism in a gram-positive bacterium. Thermoinactivation of enzyme I resulted in the loss of methyl alpha-glucoside uptake activity and enhanced sensitivity of glycerol uptake to inhibition by sugar substrates of the phosphotransferase system. The concentration of the inhibiting sugar which half maximally blocked glycerol uptake was directly related to residual enzyme I activity. Each sugar substrate of the phosphotransferase system inhibited glycerol uptake provided that the enzyme II specific for that sugar was induced to a sufficiently high level. The results support the conclusion that the phosphotransferase system regulates glycerol uptake in B. subtilis and perhaps in other gram-positive bacteria.

Documentos Relacionados

• Physiological studies on regulation of glycerol utilization by the phosphoenolpyruvate:sugar phosphotransferase system in Enterococcus faecalis.
• Phosphoenolpyruvate:sugar phosphotransferase system in Ancalomicrobium adetum.
• Phosphoenolpyruvate:sugar phosphotransferase system-mediated regulation of carbohydrate metabolism in Salmonella typhimurium.
• Interaction between IIIGlc of the phosphoenolpyruvate:sugar phosphotransferase system and glycerol kinase of Salmonella typhimurium.
• Phosphoenolpyruvate-sugar phosphotransferase transport system of Streptococcus mutans: purification of HPr and enzyme I and determination of their intracellular concentrations by rocket immunoelectrophoresis.