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.

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.

Glycosyl hydrolases family 25.

Cpl-1 lysin (also known as Cpl-9 lysozyme / muramidase) is a bacterial cell wall endolysin encoded by the pneumococcal bacteriophage Cp-1, which cleaves the glycosidic N-acetylmuramoyl-(beta1,4)-N-acetylglucosamine bonds of the pneumococcal glycan chain, thus acting as an enzymatic antimicrobial agent (an enzybiotic) against streptococcal infections. Cpl-1 belongs to the CP family of lysozymes (CPL lysozymes) which includes the Cpl-7 lysin. Cpl-1 has a glycosyl hydrolase family 25 (GH25) catalytic domain with an irregular (beta/alpha)5-beta3 barrel and a C-terminal cell wall-anchoring module formed by six similar choline-binding repeats (ChBr's). The ChBr's facilitate the anchoring of Cpl-1 to the choline-containing teichoic acid of the pneumococcal cell wall. Other members of this domain family have an N-terminal CHAP (cysteine, histidine-dependent amidohydrolases/peptidases) domain similar to that of the firmicute CHAP lysins and associated with endopeptidase activity. The Cpl-7 lysin is also included here as is LysB of Lactococcus phage, and the Mur lysin of Lactobacillus phage.

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.

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

Thecrystal structure of Ly7917 [Streptococcus phage phi7917],5D74_B The crystal structure of Ly7917 [Streptococcus phage phi7917],5D76_A The crystal structure of Ly7917 with the hydrolyzing product of MDP [Streptococcus phage phi7917],5D76_B The crystal structure of Ly7917 with the hydrolyzing product of MDP [Streptococcus phage phi7917]

N-acetylmuramoyl-L-alanine amidase sle1 OS=Staphylococcus haemolyticus (strain JCSC1435) OX=279808 GN=sle1 PE=3 SV=1

N-acetylmuramoyl-L-alanine amidase sle1 OS=Staphylococcus saprophyticus subsp. saprophyticus (strain ATCC 15305 / DSM 20229 / NCIMB 8711 / NCTC 7292 / S-41) OX=342451 GN=sle1 PE=3 SV=1

Probable cell wall hydrolase LytN OS=Staphylococcus aureus (strain MRSA252) OX=282458 GN=lytN PE=3 SV=2

Probable cell wall hydrolase LytN OS=Staphylococcus aureus (strain NCTC 8325 / PS 47) OX=93061 GN=lytN PE=2 SV=2

Probable cell wall hydrolase LytN OS=Staphylococcus aureus (strain MSSA476) OX=282459 GN=lytN PE=3 SV=2