This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Berman, M. Articles by Lin, E. C. C. Search for Related Content PubMed PubMed Citation Articles by Berman, M. Articles by Lin, E. C. C.

Glycerol-Specific Revertants of a Phosphoenolpyruvate Phosphotransferase Mutant: Suppression by the Desensitization of Glycerol Kinase to Feedback Inhibition

¹ Department of Bacteriology and Immunology, Harvard Medical School, Boston, Massachusetts 02115

ABSTRACT

Glycerol-specific revertants were isolated from a phosphoenolpyruvate phosphotransferase mutant lacking enzyme I activity. Sixteen of the eighteen separately derived revertants were found to synthesize a fully active glycerol kinase no longer subject to feedback inhibition by fructose 1,6-diphosphate. The suppressor mutation mapped at the known glpK locus. When the fructose, 1,6-diphosphate-insensitive kinase allele was transduced into a strain producing the glp enzymes constitutively, cells of the resultant strain were susceptible to killing by glycerol if this compound was added to a culture growing exponentially in casein hydrolysate. This phenomenon had been previously described for a strain which had a constitutive glycerol kinase refractory to feedback inhibition, but isolated by a different procedure. It is suggested that the suppression of the growth defect on glycerol in the enzyme I^– mutant by the fructose 1,6-diphosphate-insensitive kinase is achieved by increasing the in vivo catalytic potential of glycerol kinase. This increased activity would allow more rapid conversion of glycerol to L--glycerophosphate, the true inducer of the glp system. The enzyme I defect in the parental strain impaired the inducibility of the glp system so that the normal basal catalytic activity of the kinase was insufficient to insure induction by glycerol.

This article has been cited by other articles:

• Hardie, K. R., Cooksley, C., Green, A. D., Winzer, K. (2003). Autoinducer 2 activity in Escherichia coli culture supernatants can be actively reduced despite maintenance of an active synthase, LuxS. Microbiology 149: 715-728 [Abstract] [Full Text]  
• Holtman, C. K., Pawlyk, A. C., Meadow, N. D., Pettigrew, D. W. (2001). Reverse Genetics of Escherichia coli Glycerol Kinase Allosteric Regulation and Glucose Control of Glycerol Utilization In Vivo. J. Bacteriol. 183: 3336-3344 [Abstract] [Full Text]