Glycoside hydrolase family 19, chitinase domain. Chitinases are enzymes that catalyze the hydrolysis of the beta-1,4-N-acetyl-D-glucosamine linkages in chitin polymers. Glycoside hydrolase family 19 chitinases are found primarily in plants (classes I, III, and IV), but some are found in bacteria. Class I and II chitinases are similar in their catalytic domains. Class I chitinases have an N-terminal cysteine-rich, chitin-binding domain which is separated from the catalytic domain by a proline and glycine-rich hinge region. Class II chitinases lack both the chitin-binding domain and the hinge region. Class IV chitinases are similar to class I chitinases, but they are smaller in size due to certain deletions. Despite lacking any significant sequence homology with lysozymes, structural analysis reveals that family 19 chitinases, together with family 46 chitosanases, are similar to several lysozymes including those from T4-phage and from goose. The structures reveal that the different enzyme groups arose from a common ancestor glycohydrolase antecedent to the prokaryotic/eukaryotic divergence.

Chitinase class I.

Predicted chitinase [General function prediction only].

Chitin-binding domain of chitinase C. Chitin-binding domain of chitinase C (ChiC) of Streptomyces griseus and related proteins. Chitinase C is a family 19 chitinase, and consists of a N-terminal chitin binding domain and a C-terminal chitin-catalytic domain that effects degradation. Chitinases function in invertebrates in the degradation of old exoskeletons, in fungi to utilize chitin in cell walls, and in bacteria which use chitin as an energy source. ChiC contains the characteristic chitin-binding aromatic residues.

Chitin/cellulose binding domains of chitinase and related enzymes. This group contains proteins related to the cellulose-binding domain of Erwinia chrysanthemi endoglucanase Z (EGZ) and Serratia marcescens chitinase B (ChiB). Gram negative plant parasite Erwinia chrysanthemi produces a variety of depolymerizing enzymes to metabolize pectin and cellulose on the host plant. Cellulase EGZ has a modular structure, with an N-terminal catalytic domain linked to a C-terminal cellulose-binding domain (CBD). CBD mediates the secretion activity of EGZ. Chitinases allow certain bacteria to utilize chitin as a energy source. Typically, non-plant chitinases are of the glycosidase family 18. Bacillus circulans Glycosidase ChiA1 hydrolyzes chitin and is comprised of several domains: the C-terminal chitin binding domain, an N-terminal catalytic domain, and 2 fibronectin type III-like domains. Bacillus circulans WL-12 ChiA1 facilitates invasion of fungal cell walls. The ChiA1 chitin binding domain is required for the specific recognition of insoluble chitin. although topologically and structurally related, ChiA1 lacks the characteristic aromatic residues of Erwinia chrysanthemi endoglucanase Z (CBD(EGZ)). Streptomyces griseus Chitinase C is a family 19 chitinase, and consists of a N-terminal chitin binding domain and a C-terminal chitin-catalytic domain that effects degradation. ChiC contains the characteristic chitin-binding aromatic residues. Chitinases function in invertebrates in the degradation of old exoskeletons, in fungi to utilize chitin in cell walls, and in bacteria which use chitin as an energy source.

Crystalstructure of chitinase C from Streptomyces griseus HUT6037 [Streptomyces griseus],1WVU_B Crystal structure of chitinase C from Streptomyces griseus HUT6037 [Streptomyces griseus],2DBT_A Crystal structure of chitinase C from Streptomyces griseus HUT6037 [Streptomyces griseus],2DBT_B Crystal structure of chitinase C from Streptomyces griseus HUT6037 [Streptomyces griseus],2DBT_C Crystal structure of chitinase C from Streptomyces griseus HUT6037 [Streptomyces griseus]

ChainA, chitinase C [Streptomyces griseus],1WVV_B Chain B, chitinase C [Streptomyces griseus]

CrystalStructure And Enzymatic Properties Of A Bacterial Family 19 Chitinase Reveal Differences With Plant Enzymes [Streptomyces coelicolor],2CJL_B Crystal Structure And Enzymatic Properties Of A Bacterial Family 19 Chitinase Reveal Differences With Plant Enzymes [Streptomyces coelicolor]

CrystalStructure of a Family GH19 Chitinase from Bryum coronatum in complex with (GlcNAc)4 at 1.0 A resolution [Gemmabryum coronatum]

CrystalStructure of a Family GH19 chitinase from Bryum coronatum in complex with (GlcNAc)4 [Gemmabryum coronatum]

Endochitinase 4 OS=Cryptomeria japonica OX=3369 PE=1 SV=1

Chitinase 6 OS=Oryza sativa subsp. japonica OX=39947 GN=Cht6 PE=2 SV=1

Endochitinase A OS=Zea mays OX=4577 GN=CHIA PE=1 SV=1

Chitinase 4 OS=Oryza sativa subsp. japonica OX=39947 GN=Cht4 PE=2 SV=2

Chitinase 3 OS=Oryza sativa subsp. japonica OX=39947 GN=Cht3 PE=2 SV=2