Mutants of 4-oxalocrotonate tautomerase catalyze the decarboxylation of oxaloacetate through an imine mechanism

Ashraf Brik, Lawrence J. D'Souza, Ehud Keinan, Flavio Grynszpan, Philip E. Dawson

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

A designed single amino acid substitution can alter the catalytic activity and mechanism of 4-oxalocrotonate tautomerase (4-OT). While the wild-type enzyme catalyzes only the tautomerization of oxalocrotonate, the ProlAla mutant (P1A) catalyzes two reactions - the original tautomerization reaction and the decarboxylation of oxaloacetate. Although the N-terminal amine group of P1A is involved in both reactions, our results support a nucleophilic mechanism for the decarboxylase activity, in contrast to the general acid/base mechanism that has been previously established for the tautomerase activity. These findings demonstrate that a single catalytic group in a 4-OT mutant can catalyze two reactions by two different mechanisms.

Original languageEnglish
Pages (from-to)845-851
Number of pages7
JournalChemBioChem
Volume3
Issue number9
DOIs
StatePublished - 1 Dec 2002
Externally publishedYes

Keywords

  • Decarboxylation
  • Imines
  • Oxaloacetate
  • Protein engineering
  • Tautomerases

Fingerprint

Dive into the research topics of 'Mutants of 4-oxalocrotonate tautomerase catalyze the decarboxylation of oxaloacetate through an imine mechanism'. Together they form a unique fingerprint.

Cite this