Crystal Structures of Cystathionine β-Synthase from Saccharomyces cerevisiae: One Enzymatic Step at a Time Academic Article uri icon

Overview

MeSH Major

  • Autophagy
  • Indoles
  • Neuroprotective Agents
  • alpha-Synuclein

abstract

  • © 2018 American Chemical Society. Cystathionine β-synthase (CBS) is a key regulator of sulfur amino acid metabolism, taking homocysteine from the methionine cycle to the biosynthesis of cysteine via the trans-sulfuration pathway. CBS is also a predominant source of H 2 S biogenesis. Roles for CBS have been reported for neuronal death pursuant to cerebral ischemia, promoting ovarian tumor growth, and maintaining drug-resistant phenotype by controlling redox behavior and regulating mitochondrial bioenergetics. The trans-sulfuration pathway is well-conserved in eukaryotes, but the analogous enzymes have different enzymatic behavior in different organisms. CBSs from the higher organisms contain a heme in an N-terminal domain. Though the presence of the heme, whose functions in CBSs have yet to be elucidated, is biochemically interesting, it hampers UV-vis absorption spectroscopy investigations of pyridoxal 5′-phosphate (PLP) species. CBS from Saccharomyces cerevisiae (yCBS) naturally lacks the heme-containing N-terminal domain, which makes it an ideal model for spectroscopic studies of the enzymological reaction catalyzed and allows structural studies of the basic yCBS catalytic core (yCBS-cc). Here we present the crystal structure of yCBS-cc, solved to 1.5 Å. Crystal structures of yCBS-cc in complex with enzymatic reaction intermediates have been captured, providing a structural basis for residues involved in catalysis. Finally, the structure of the yCBS-cc cofactor complex generated by incubation with an inhibitor shows apparent off-pathway chemistry not normally seen with CBS.

publication date

  • June 5, 2018

Research

keywords

  • Academic Article

Identity

Language

  • eng

Digital Object Identifier (DOI)

  • 10.1021/acs.biochem.8b00092

PubMed ID

  • 29630349

Additional Document Info

start page

  • 3134

end page

  • 3145

volume

  • 57

number

  • 22