Significance of the enzymatic properties of yeast S39A enolase to the catalytic mechanism.
The S39A mutant of yeast enolase (isozyme 1), prepared by site-directed mutagenesis, has a relative Vmax of 0.01% and an activation constant for Mg2+ ca. 10-fold higher, compared with native enzyme. It is correctly folded. There is little effect of solvent viscosity on activity. We think that the loop Ser36-His43 fails to move to the 'closed' position upon catalytic Mg2+ binding, weakening several electrostatic interactions involved in the mechanism.
Brewer
J M
JM
Dept. of Biochemistry and Molecular Biology, University of Georgia, Athens 30602, USA.
Glover
C V
CV
Holland
M J
MJ
Lebioda
L
L
D009154:Mutation; D010751:Phosphopyruvate Hydratase / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D010751:Phosphopyruvate Hydratase