Disease relevance of amiC

• Pneumococcal peptidoglycan amidase (N-acetylmuramoyl-L-alanine amidase, EC 3.5.1.28) and phage CPL1 lysozyme degrade a common substrate (choline-containing pneumococcal cell walls); the former hydrolyzes the bond between muramic acid and alanine, whereas the latter breaks down the linkage between muramic acid and glucosamine [1].
• The major pneumococcal autolysin (N-acetylmuramoyl-L-alanine amidase) has been localized in the cellular envelope of Streptococcus pneumoniae and Escherichia coli by using immunocytochemical labeling on ultrathin sections and whole-mounted cells [2].
• The predicted amino acid sequence of this 48 kDa polypeptide shows homology to the major N-acetylmuramoyl-L-alanine amidase autolysin of Bacillus subtilis, a known amidase of Bacillus licheniformis, and the product of a Salmonella typhimurium gene that maps near 50 min [3].
• The N-acetylmuramoyl-L-alanine amidase encoded by the Bacillus subtilis 168 prophage SP beta [4].
• The enzyme purified from the E. coli clone is an N-acetylmuramoyl-L-alanine amidase, which has a M(r) value of 41 kDa as determined by SDS-polyacrylamide gel electrophoresis, and is able to digest B. licheniformis, B. subtilis and Micrococcus luteus cell walls [5].

High impact information on amiC

• This mutant phenotype is the first found for an N-acetylmuramoyl-l-alanine amidase PGRP that cleaves peptidoglycan at the lactylamide bond between the glycan backbone and the crosslinking stem peptides [6].
• CwlH produced in Escherichia coli harboring a cwlH plasmid is an N-acetylmuramoyl-L-alanine amidase (EC 3.5.1.28) and exhibited an optimum pH of 7.0 and high-level binding to the B. subtilis cell wall [7].
• A major Bacillus subtilis 168S autolysin (N-acetylmuramoyl-L-alanine amidase [EC 3.5.1.28]) was purified and then cleaved with cyanogen bromide [8].
• Identification of the structural genes for N-acetylmuramoyl-L-alanine amidase and its modifier in Bacillus subtilis 168: inactivation of these genes by insertional mutagenesis has no effect on growth or cell separation [9].
• Another ORF (lys) consisted of 1050 bp encoding an N-acetylmuramoyl-L-alanine amidase of 350 amino acids [10].

Biological context of amiC

• The upstream region of the N-acetylmuramoyl-L-alanine amidase gene (cwlB; a major Bacillus subtilis autolysin) was cloned into Escherichia coli by chromosome walking [11].

References