Structural and Functional Characterization of Cystathionine γ-lyase from Bacillus cereus ATCC 14579

J Agric Food Chem. 2020 Dec 23;68(51):15267-15274. doi: 10.1021/acs.jafc.0c06503. Epub 2020 Dec 10.

Abstract

Cysteine is a semiessential amino acid and plays an important role in metabolism and protein structure and has also been applied in various industrial fields, such as pharmaceutical, food, cosmetic, and animal feed industries. Metabolic engineering studies have been conducted for the cysteine production through bacterial fermentation, but studies on the cysteine biosynthetic pathway in microorganisms are limited. We report the biochemical characteristics of cystathionine γ-lyase from Bacillus cereus ATCC 14579 (BcCGL). We also determined the crystal structure of BcCGL in complex with the PLP cofactor and identified the substrate binding mode. We observed that the replacement of the conserved Glu321 residue to alanine showed increased activity by providing wider active site entrance and hydrophobic interaction for the substrate. We suggest that the structural differences of the α13-α14 region in CGL enzymes might determine the active site conformation.

Keywords: Bacillus cereus; crystal structure; cystathionine γ-lyase; cysteine biosynthesis.

MeSH terms

  • Bacillus cereus / chemistry
  • Bacillus cereus / enzymology*
  • Bacillus cereus / genetics
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Binding Sites
  • Catalytic Domain
  • Cystathionine gamma-Lyase / chemistry*
  • Cystathionine gamma-Lyase / genetics
  • Cystathionine gamma-Lyase / metabolism*
  • Cysteine / metabolism
  • Kinetics
  • Substrate Specificity

Substances

  • Bacterial Proteins
  • Cystathionine gamma-Lyase
  • Cysteine