Site-directed mutagenesis of histidine 62 in the 'basic patch' region of yeast phosphoglycerate kinase.
Site-directed mutagenesis has been used to produce a mutant form of yeast phosphoglycerate kinase (PGK) in which the 'basic patch' residue His 62 has been replaced by a glutamine residue. Using 1H-NMR spectroscopy, it was found that 3-phosphoglycerate (3-PG) binding to the mutant protein induces the same conformational effects as for wild-type PGK, although the affinity was reduced by 2- to 3-fold. Kinetic studies show both Km for 3-PG and Vmax to be increased by approximately 2-fold relative to the wild-type enzyme. These data are consistent with the suggestion that His 62 assists in the binding of the substrate to the enzyme.
Fairbrother
W J
WJ
Inorganic Chemistry Laboratory, Oxford, England.
Hall
L
L
Littlechild
J A
JA
Walker
P A
PA
Watson
H C
HC
Williams
R J
RJ
D006639:Histidine; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D009154:Mutation; D010735:Phosphoglycerate Kinase / Q000235:genetics* / Q000378:metabolism; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics
D006639:Histidine; D010735:Phosphoglycerate Kinase