Glyoxylate carboligase lacks the canonical active site glutamate of thiamine-dependent enzymes

Alexander Kaplun, Elad Binshtein, Maria Vyazmensky, Andrea Steinmetz, Ze'ev Barak, David M. Chipman, Kai Tittmann, Boaz Shaanan

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


Thiamine diphosphate (ThDP), a derivative of vitamin B1, is an enzymatic cofactor whose special chemical properties allow it to play critical mechanistic roles in a number of essential metabolic enzymes. It has been assumed that all ThDP-dependent enzymes exploit a polar interaction between a strictly conserved glutamate and the N1′ of the ThDP moiety. The crystal structure of glyoxylate carboligase challenges this paradigm by revealing that valine replaces the conserved glutamate. Through kinetic, spectroscopic and site-directed mutagenesis studies, we show that although this extreme change lowers the rate of the initial step of the enzymatic reaction, it ensures efficient progress through subsequent steps. Glyoxylate carboligase thus provides a unique illustration of the fine tuning between catalytic stages imposed during evolution on enzymes catalyzing multistep processes.

Original languageEnglish
Pages (from-to)113-118
Number of pages6
JournalNature Chemical Biology
Issue number2
StatePublished - 1 Jan 2008

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'Glyoxylate carboligase lacks the canonical active site glutamate of thiamine-dependent enzymes'. Together they form a unique fingerprint.

Cite this