Structure of human cystathionine beta-synthase: a unique pyridoxal 5'-phosphate-dependent heme protein

EMBO J. 2001 Aug 1;20(15):3910-6. doi: 10.1093/emboj/20.15.3910.

Abstract

Cystathionine beta-synthase (CBS) is a unique heme- containing enzyme that catalyzes a pyridoxal 5'-phosphate (PLP)-dependent condensation of serine and homocysteine to give cystathionine. Deficiency of CBS leads to homocystinuria, an inherited disease of sulfur metabolism characterized by increased levels of the toxic metabolite homocysteine. Here we present the X-ray crystal structure of a truncated form of the enzyme. CBS shares the same fold with O-acetylserine sulfhydrylase but it contains an additional N-terminal heme binding site. This heme binding motif together with a spatially adjacent oxidoreductase active site motif could explain the regulation of its enzyme activity by redox changes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Cystathionine beta-Synthase / chemistry*
  • Cystathionine beta-Synthase / genetics
  • Cystathionine beta-Synthase / metabolism
  • Heme / metabolism
  • Hemeproteins / chemistry*
  • Hemeproteins / genetics
  • Hemeproteins / metabolism
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Mutagenesis
  • Oxidoreductases / metabolism
  • Protein Structure, Secondary
  • Pyridoxal Phosphate / metabolism*
  • Rabbits

Substances

  • Hemeproteins
  • Heme
  • Pyridoxal Phosphate
  • Oxidoreductases
  • Cystathionine beta-Synthase

Associated data

  • PDB/1JBQ