LysA is a cell wall endolysin produced by Lactobacillus fermentum, which degrades bacterial cell walls by catalyzing the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues. The N-terminal glycosyl hydrolase family 25 (GH25) domain of LysA has sequence similarity with other murein hydrolase catalytic domains while the C-terminal domain has sequence similarity with putative bacterial cell wall-binding SH3b domains. This domain family also includes LysL of Lactococcus lactis.

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.

CH-type (Chalaropsis-type) lysozymes represent one of four functionally-defined classes of peptidoglycan hydrolases (also referred to as endo-N-acetylmuramidases) that cleave bacterial cell wall peptidoglycans. CH-type lysozymes exhibit both lysozyme (acetylmuramidase) and diacetylmuramidase activity. The first member of this family to be described was a muramidase from the fungus Chalaropsis. However, a majority of the CH-type lysozymes are found in bacteriophages and Gram-positive bacteria such as Streptomyces and Clostridium. CH-type lysozymes have a single glycosyl hydrolase family 25 (GH25) domain with an unusual beta/alpha-barrel fold in which the last strand of the barrel is antiparallel to strands beta7 and beta1. Most CH-type lysozymes appear to lack the cell wall-binding domain found in other GH25 muramidases.

Crystalstructure of the bacterial lysozyme from Streptomyces coelicolor at 1.65 A resolution [Streptomyces coelicolor]

X-raystructure of catalytic domain of endolysin from clostridium perfringens phage phiSM101 [Clostridium phage phiSM101]

X-raystructure of endolysin from clostridium perfringens phage phiSM101 [Clostridium phage phiSM101],4KRT_B X-ray structure of endolysin from clostridium perfringens phage phiSM101 [Clostridium phage phiSM101]

Crystalstructure of the Clostridium perfringens spore cortex lytic enzyme SleM [Clostridium perfringens],5JIP_B Crystal structure of the Clostridium perfringens spore cortex lytic enzyme SleM [Clostridium perfringens]

Thestructure of a family GH25 lysozyme from Aspergillus fumigatus [Aspergillus fumigatus Af293],2X8R_B The structure of a family GH25 lysozyme from Aspergillus fumigatus [Aspergillus fumigatus Af293],2X8R_C The structure of a family GH25 lysozyme from Aspergillus fumigatus [Aspergillus fumigatus Af293],2X8R_D The structure of a family GH25 lysozyme from Aspergillus fumigatus [Aspergillus fumigatus Af293],2X8R_E The structure of a family GH25 lysozyme from Aspergillus fumigatus [Aspergillus fumigatus Af293],2X8R_F The structure of a family GH25 lysozyme from Aspergillus fumigatus [Aspergillus fumigatus Af293]

Lysozyme M1 OS=Streptomyces globisporus OX=1908 GN=acm PE=1 SV=1

N,O-diacetylmuramidase OS=Chalaropsis sp. OX=36534 PE=1 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

N-acetylmuramoyl-L-alanine amidase sle1 OS=Staphylococcus epidermidis (strain ATCC 12228 / FDA PCI 1200) OX=176280 GN=sle1 PE=3 SV=1

N-acetylmuramoyl-L-alanine amidase sle1 OS=Staphylococcus epidermidis (strain ATCC 35984 / RP62A) OX=176279 GN=sle1 PE=3 SV=1