Cortical fragment-lytic enzyme (CFLE) is a peptidoglycan hydrolase involved in bacterial endospore germination. CFLE is expressed as an inactive preprotein (called SleB) in the forespore compartment of sporulating cells. SleB translocates across the forespore inner membrane and is deposited as a mature enzyme in the cortex layer of the spore. As part of a sensory mechanism capable of initiating germination, CFLE degrades a spore-specific peptidoglycan constituent called muramic-acid delta-lactam that comprises the outer cortex. CFLE has a C-terminal glycosyl hydrolase family 18 (GH18) catalytic domain as well as two N-terminal LysM peptidoglycan-binding domains. In addition to SleB, this family includes YaaH, YdhD, and YvbX from Bacillus subtilis.

Spore germination protein YaaH [Cell cycle control, cell division, chromosome partitioning].

Chitobiase (also known as di-N-acetylchitobiase) is a lysosomal glycosidase that hydrolyzes the reducing-end N-acetylglucosamine from the chitobiose core of oligosaccharides during the ordered degradation of asparagine-linked glycoproteins in eukaryotes. Chitobiase can only do so if the asparagine that joins the oligosaccharide to protein is previously removed by a glycosylasparaginase. Chitobiase is therefore the final step in the lysosomal degradation of the protein/carbohydrate linkage component of asparagine-linked glycoproteins. The catalytic domain of chitobiase is an eight-stranded alpha/beta barrel fold similar to that of other family 18 glycosyl hydrolases such as hevamine and chitotriosidase.

Stabilin-1 interacting chitinase-like protein (SI-CLP) is a eukaryotic chitinase-like protein of unknown function that interacts with the endocytic/sorting transmembrane receptor stabilin-1 and is secreted from the lysosome. SI-CLP has a glycosyl hydrolase family 18 (GH18) domain but lacks a chitin-binding domain. The catalytic amino acids of the GH18 domain are not conserved in SI-CLP, similar to the chitolectins YKL-39, YKL-40, and YM1/2. Human SI-CLP is sorted to late endosomes and secretory lysosomes in alternatively activated macrophages.

Glycosyl hydrolases family 18.

ChainA, Putative sporulation-specific glycosylase ydhD [Bacillus subtilis subsp. subtilis str. 168],3CZ8_B Chain B, Putative sporulation-specific glycosylase ydhD [Bacillus subtilis subsp. subtilis str. 168]

Thecrystal structure of a class V chitininase from Pseudomonas fluorescens Pf-5 [Pseudomonas protegens Pf-5]

Crystalstructure of chitinase from Chromobacterium violaceum ATCC 12472 [Chromobacterium violaceum ATCC 12472]

ChainA, Spore germination protein YaaH [Priestia megaterium QM B1551]

Crystalstructure of the Bacillus cereus spore cortex-lytic enzyme SleL [Bacillus cereus ATCC 10876],4S3J_B Crystal structure of the Bacillus cereus spore cortex-lytic enzyme SleL [Bacillus cereus ATCC 10876],4S3J_C Crystal structure of the Bacillus cereus spore cortex-lytic enzyme SleL [Bacillus cereus ATCC 10876]

Uncharacterized glycosylase YvbX OS=Bacillus subtilis (strain 168) OX=224308 GN=yvbX PE=3 SV=1

Putative sporulation-specific glycosylase YdhD OS=Bacillus subtilis (strain 168) OX=224308 GN=ydhD PE=1 SV=2

Cortical fragment-lytic enzyme OS=Bacillus subtilis (strain 168) OX=224308 GN=sleL PE=1 SV=2

Putative glycosylase YkvQ OS=Bacillus subtilis (strain 168) OX=224308 GN=ykvQ PE=3 SV=1

Cortical fragment-lytic enzyme OS=Bacillus anthracis OX=1392 GN=sleL PE=2 SV=1