Автолизин ферменттері және пептидогликан метаболизмі

Class of enzymes
Autolysins are endogenous lytic enzymes that break down the peptidoglycan components of biological cells which enables the separation of daughter cells following cell division. They are involved in cell growth, cell wall metabolism, cell division and separation, as well as peptidoglycan turnover and have similar functions to lysozymes. Autolysin is formed from the precursor gene, Atl. Amidases (EC 3.5.1.28), gametolysin (EC 3.4.24.38), and glucosaminidase are considered as types of autolysins. They target the glycosidic bonds as well as the cross linked peptides of the peptidoglycan matrix. The peptidoglycan matrix functions for cell wall stability to protect from turgor changes and carries out function for immunological defense. These enzymes break down the peptidoglycan matrix in small sections to allow for peptidoglycan biosynthesis. The amide linkages between stem peptide and lactyl moiety of muramoyl residue are cleaved by N acetylmuramoyl l alanine amidases and partakes in cell separation and the dissociation of the cell septum.

LytC and CwlC are two amidases from the LytC family that hydrolyze the peptidoglycan of the mother cell wall to allow for the release of the mature endospore. CwlC is directly found in the mother cell wall.

CwlC is found in the mother cell wall and functions for the lysis of the mother cell wall. It was found in B. subtilis that CwlC is able to hydrolyze both vegetative cell walls and spore peptidoglycan.

This family of autolysin consist of only LytD itself. LytD functions for vegetative growth. Autolytic activity is found within the C terminal region with catalytic domain homologous to the glucosaminidase domain. LytD is found in the cell wall. LytD activity was studied in B. subtilis and glucosaminidase activity was found in mature glycan strands due to the presence of MurNAc at the nonreducing ends.