The CHAP domain: a large family of amidases including GSP amidase and peptidoglycan hydrolases

Trends Biochem Sci. 2003 May;28(5):234-7. doi: 10.1016/S0968-0004(03)00061-6.


Cleavage of peptidoglycan plays an important role in bacterial cell division, cell growth and cell lysis. Here, we reveal that several known peptidoglycan amidases fall into a family, which includes many proteins of previously unknown function. The family includes two different peptidoglycan cleavage activities: L-muramoyl-L-alanine amidase and D-alanyl-glycyl endopeptidase activity. The family includes the amidase portion of the bifunctional glutathionylspermidine synthase/amidase enzyme from bacteria and pathogenic trypanosomes. The glutathionylspermidine synthase is thought to be a key component of the alternative pathway in trypanosomes for protection from oxygen-radical damage and has been proposed as a potential drug target. The CHAP (cysteine, histidine-dependent amidohydrolases/peptidases) domain is often found in association with other domains that cleave peptidoglycan. The large number of multifunctional hydrolases suggests that they might act in a cooperative manner to cleave specialized substrates.

Publication types

  • Review

MeSH terms

  • Amidohydrolases / chemistry*
  • Amidohydrolases / metabolism*
  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism
  • Molecular Sequence Data
  • Peptidoglycan / metabolism*
  • Protein Structure, Tertiary


  • Bacterial Proteins
  • Peptidoglycan
  • Amidohydrolases
  • amidase