Crystal structures of yeast beta-alanine synthase complexes reveal the mode of substrate binding and large scale domain closure movements

Research output: Contribution to journalArticle

Abstract

β-Alanine synthase is the final enzyme of the reductive pyrimidine catabolic pathway, which is responsible for the breakdown of uracil and thymine in higher organisms. The fold of the homodimeric enzyme from the yeast Saccharomyces kluyveri identifies it as a member of the AcyI/M20 family of metallopeptidases. Its subunit consists of a catalytic domain harboring a di-zinc center and a smaller dimerization domain. The present site-directed mutagenesis studies identify Glu159 and Arg322 as crucial for catalysis and His262 and His397 as functionally important but not essential. We determined the crystal structures of wild-type β-alanine synthase in complex with the reaction product β-alanine, and of the mutant E159A with the substrate N-carbamyl-β-alanine, revealing the closed state of a dimeric AcyI/M20 metallopeptidase-like enzyme. Subunit closure is achieved by a 30° rigid body domain rotation, which completes the active site by integration of substrate binding residues that belong to the dimerization domain of the same or the partner subunit. Substrate binding is achieved via a salt bridge, a number of hydrogen bonds, and coordination to one of the zinc ions of the di-metal center.

Details

Authors
  • Stina Lundgren
  • Birgit Andersen
  • Jure Piskur
  • Doreen Dobritzsch
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biological Sciences

Keywords

  • nucleic acid precursors, structure-function, catabolism
Original languageEnglish
Pages (from-to)36037-36047
JournalJournal of Biological Chemistry
Volume282
Issue number49
Publication statusPublished - 2007
Publication categoryResearch
Peer-reviewedYes