AtlA is an autolysin found in Gram-positive lactic acid bacteria that degrades bacterial cell walls by catalyzing the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues. This family includes the AtlA and Aml autolysins from Streptococcus mutans which have a C-terminal glycosyl hydrolase family 25 (GH25) catalytic domain as well as six tandem N-terminal repeats of the GBS (group B Streptococcus) Bsp-like peptidoglycan-binding domain. Other members of this family have one or more C-terminal peptidoglycan-binding domain(s) (SH3 or LysM) in addition to the GH25 domain.

Glycosyl hydrolases family 25.

Endo-N-acetylmuramidases (muramidases) are lysozymes (also referred to as peptidoglycan hydrolases) that degrade bacterial cell walls by catalyzing the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues. This family of muramidases contains a glycosyl hydrolase family 25 (GH25) catalytic domain and is found in bacteria, fungi, slime molds, round worms, protozoans and bacteriophages. The bacteriophage members are referred to as endolysins which are involved in lysing the host cell at the end of the replication cycle to allow release of mature phage particles. Endolysins are typically modular enzymes consisting of a catalytically active domain that hydrolyzes the peptidoglycan cell wall and a cell wall-binding domain that anchors the protein to the cell wall. Endolysins generally have narrow substrate specificities with either intra-species or intra-genus bacteriolytic activity.

Lyc muramidase is an autolytic lysozyme (autolysin) from Clostridium acetobutylicum encoded by the lyc gene. Lyc has a glycosyl hydrolase family 25 (GH25) catalytic domain. Endo-N-acetylmuramidases are lysozymes (also referred to as peptidoglycan hydrolases) that degrade bacterial cell walls by catalyzing the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues.

Domain of unknown function (DUF5776). Presumed stalk domain found in bacterial surface proteins forming tandem repeats with high sequence identity. This domain is also associated with other known bacterial surface protein stalks and adhesive domains.

Crystalstructure of the CTP1L endolysin reveals how its activity is regulated by a secondary translation product [Clostridium phage phiCTP1]