OUP user menu

The negative regulator of β-lactamase induction AmpD is a N-acetyl-anhydromuramyl-l-alanine amidase

Joachim-Volker Höltje , Ursula Kopp , Astrid Ursinus , Bernd Wiedemann
DOI: http://dx.doi.org/10.1111/j.1574-6968.1994.tb07159.x 159-164 First published online: 1 September 1994


Construction of a malE-ampD gene fusion allowed purification of biologically active fusion protein by affinity chromatography. The cloned malE-ampD gene fusion complemented a chromosomal ampD mutation. Purified MalE-AmpD fusion protein was found to have murein amidase activity with a pronounced specificity for 1,6-anhydromuropeptides, the characteristic murein turnover products in Escherichia coli. Being a N-acetyl-anhydromuramyl-L-alanine amidase AmpD is likely to be involved in recycling of the turnover products. It is suggested that the negative regulatory effect of AmpD is due to the hydrolysis of anhydro-muropeptides which may function as signals for β-lactamase induction.

Key words
  • β-lactamase induction
  • AmpD
  • AmpC
  • Anhydromuropeptides
  • Murein recycling
  • Murein hydrolase
  • Amidase

Log in through your institution