Chitinase, GH18 family [Carbohydrate transport and metabolism].

The GH18 (glycosyl hydrolases, family 18) type II chitinases hydrolyze chitin, an abundant polymer of N-acetylglucosamine and have been identified in bacteria, fungi, insects, plants, viruses, and protozoan parasites. The structure of this domain is an eight-stranded alpha/beta barrel with a pronounced active-site cleft at the C-terminal end of the beta-barrel.

Glyco_18 domain.

Glycosyl hydrolases family 18.

This conserved domain family includes a large number of catalytically inactive chitinase-like lectins (chitolectins) including YKL-39, YKL-40 (HCGP39), YM1, oviductin, and AMCase (acidic mammalian chitinase), as well as catalytically active chitotriosidases. The conserved domain is an eight-stranded alpha/beta barrel fold belonging to the family 18 glycosyl hydrolases. The fold has a pronounced active-site cleft at the C-terminal end of the beta-barrel. The chitolectins lack a key active site glutamate (the proton donor required for hydrolytic activity) but retain highly conserved residues involved in oligosaccharide binding. Chitotriosidase is a chitinolytic enzyme expressed in maturing macrophages, which suggests that it plays a part in antimicrobial defense. Chitotriosidase hydrolyzes chitotriose, as well as colloidal chitin to yield chitobiose and is therefore considered an exochitinase. Chitotriosidase occurs in two major forms, the large form being converted to the small form by either RNA or post-translational processing. Although the small form, containing the chitinase domain alone, is sufficient for the chitinolytic activity, the additional C-terminal chitin-binding domain of the large form plays a role in processing colloidal chitin. The chitotriosidase gene is nonessential in humans, as about 35% of the population are heterozygous and 6% homozygous for an inactivated form of the gene. HCGP39 is a 39-kDa human cartilage glycoprotein thought to play a role in connective tissue remodeling and defense against pathogens.

Cryo-EMstructure of YenTcA in its prepore state [Yersinia entomophaga],6OGD_F Cryo-EM structure of YenTcA in its prepore state [Yersinia entomophaga],6OGD_I Cryo-EM structure of YenTcA in its prepore state [Yersinia entomophaga],6OGD_L Cryo-EM structure of YenTcA in its prepore state [Yersinia entomophaga],6OGD_O Cryo-EM structure of YenTcA in its prepore state [Yersinia entomophaga]

CrystalStructure of a chitinase from the Yersinia entomophaga toxin complex [Yersinia entomophaga]

CrystalStructure of a chitinase from the Yersinia entomophaga toxin complex [Yersinia entomophaga]

Crystalstructure of the chitinase Chi1 fitted into the 3D structure of the Yersinia entomophaga toxin complex [Yersinia entomophaga],4A5Q_B Crystal structure of the chitinase Chi1 fitted into the 3D structure of the Yersinia entomophaga toxin complex [Yersinia entomophaga],4A5Q_C Crystal structure of the chitinase Chi1 fitted into the 3D structure of the Yersinia entomophaga toxin complex [Yersinia entomophaga],4A5Q_D Crystal structure of the chitinase Chi1 fitted into the 3D structure of the Yersinia entomophaga toxin complex [Yersinia entomophaga],4A5Q_E Crystal structure of the chitinase Chi1 fitted into the 3D structure of the Yersinia entomophaga toxin complex [Yersinia entomophaga]

Thestructure of chi1, a chitinase from Yersinia entomophaga [Yersinia entomophaga],3OA5_B The structure of chi1, a chitinase from Yersinia entomophaga [Yersinia entomophaga]

Chitinase 2 OS=Yersinia entomophaga OX=935293 GN=chi2 PE=1 SV=1

Chitinase 1 OS=Yersinia entomophaga OX=935293 GN=chi1 PE=1 SV=1

Chitinase A OS=Pseudoalteromonas piscicida OX=43662 GN=chiA PE=1 SV=1

Chitinase A1 OS=Niallia circulans OX=1397 GN=chiA1 PE=1 SV=1

Chitinase A OS=Serratia marcescens OX=615 GN=chiA PE=1 SV=3