Functional and metabolic effects of adaptive glycerol kinase (GLPK) mutants in Escherichia coli.

ABSTRACT: Herein we measure the effect of four adaptive non-synonymous mutations to the glycerol kinase (glpK) gene on catalytic function and regulation, to identify changes that correlate to increased fitness in glycerol media. The mutations significantly reduce affinity for the allosteric inhibitor fructose-1,6-bisphosphate (FBP) and formation of the tetramer, which are structurally related, in a manner that correlates inversely with imparted fitness during growth on glycerol, which strongly suggests that these enzymatic parameters drive growth improvement. Counterintuitively, the glpK mutations also increase glycerol-induced auto-catabolite repression that reduces glpK transcription in a manner that correlates to fitness. This suggests that increased specific GlpK activity is attenuated by negati

SUBMITTER: Applebee MK 

PROVIDER: S-EPMC3123082 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature