Effect of cysteine desulfhydrase gene disruption on L-cysteine overproduction in Escherichia coli

Appl Microbiol Biotechnol. 2003 Aug;62(2-3):239-43. doi: 10.1007/s00253-003-1262-2. Epub 2003 Mar 20.


In Escherichia coli, the enzyme called cysteine desulfhydrase (CD), which is responsible for L-cysteine degradation, was investigated by native-PAGE and CD activity staining of crude cell extracts. Analyses with gene-disrupted mutants showed that CD activity resulted from two enzymes: tryptophanase (TNase) encoded by tnaA and cystathionine beta-lyase (CBL) encoded by metC. It was also found that TNase synthesis was induced by the presence of L-cysteine. The tnaA and metC mutants transformed with the plasmid containing the gene for feedback-insensitive serine acetyltransferase exhibited higher L-cysteine productivity than the wild-type strain carrying the same plasmid. These results indicated that TNase and CBL did act on L-cysteine degradation in E. coli cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cystathionine gamma-Lyase / genetics*
  • Cystathionine gamma-Lyase / metabolism
  • Cysteine / biosynthesis*
  • DNA, Bacterial / genetics
  • Enzyme Induction
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism*
  • Gene Targeting
  • Genes, Bacterial*
  • Lyases / biosynthesis
  • Lyases / genetics
  • Mutagenesis, Insertional
  • Tryptophanase / biosynthesis
  • Tryptophanase / genetics


  • DNA, Bacterial
  • Lyases
  • Tryptophanase
  • Cystathionine gamma-Lyase
  • cystathionine beta-lyase
  • Cysteine