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Catalytic Site Atlas

CSA LITERATURE entry for 5enl

E.C. namephosphopyruvate hydratase
SpeciesSaccharomyces cerevisiae (Baker's yeast)
E.C. Number (IntEnz)
CSA Homologues of 5enlThere are 38 Homologs
CSA Entries With UniProtID P00924
CSA Entries With EC Number
PDBe Entry 5enl
PDBSum Entry 5enl
MACiE Entry M0311

Literature Report

IntroductionEnolase catalyses a key reaction in glycolysis, and is present in all organisms that metabolise sugar. The best characterised isozyme is that from yeast, and there are three different isozymes present in vertebrates.
MechansimExtensive study of this enzyme has revealed its mechanism in detail, and therefore made it possible to characterise part reactions of site-directed mutants using isotope effects. From these it is clear that Lys345 must act as the major catalytic base, abstracting a proton from 2-phosphoglycerate. Less obvious is the nature of the catalytic acid that protonates the departing hydroxy group; mutations of Glu211 primarily affect this second part-reaction, and this residue is suitably positioned to act as the base. Glu168 also appears critical from the adverse effects of mutating it, but its role cannot be localised to either part reaction; more recently, mutagenesis has suggested a role for His373. Perhaps the most likely interpretation of the data is that Glu168 and Glu211 share a proton which they donate to the leaving group, to which His373 forms a stabilising hydrogen bond (the fact that an H373N mutant retains 10% activity rules out and acid/base role for this residue).
Tau crystallin, one of the major lens proteins of birds, fish and reptiles, is also evolutionarily related to enolase.

Catalytic Sites for 5enl

Annotated By Reference To The Literature - Site 2 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription

Literature References

Poyner RR
Toward identification of acid/base catalysts in the active site of enolase: comparison of the properties of K345A, E168Q, and E211Q variants.
Biochemistry 1996 35 1692-1699
PubMed: 8634301
Brewer JM
Effect of site-directed mutagenesis of His373 of yeast enolase on some of its physical and enzymatic properties.
Biochim Biophys Acta 1997 1340 88-96
PubMed: 9217018