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.

Chitodextrinase [Carbohydrate transport and metabolism].

Chitinase class I.

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-binding domain type 3.

ChainA, GH19 Chitinase [Ficus microcarpa],7V91_B Chain B, GH19 Chitinase [Ficus microcarpa],7V91_C Chain C, GH19 Chitinase [Ficus microcarpa],7V91_D Chain D, GH19 Chitinase [Ficus microcarpa]

ChainA, GH19 Chitinase [Ficus microcarpa],7V92_B Chain B, GH19 Chitinase [Ficus microcarpa],7V92_C Chain C, GH19 Chitinase [Ficus microcarpa],7V92_D Chain D, GH19 Chitinase [Ficus microcarpa]

Crystalstructure of chitinase (GH19) from Vigna unguiculata [Vigna unguiculata subsp. sesquipedalis]

Crystalstructure of class I chitinase from Oryza sativa L. japonica [Oryza sativa Japonica Group],3IWR_A Crystal structure of class I chitinase from Oryza sativa L. japonica [Oryza sativa Japonica Group],3IWR_B Crystal structure of class I chitinase from Oryza sativa L. japonica [Oryza sativa Japonica Group]

CrystalStructure of a putative catalytic domain of a chitinase-like protein (HbCLP1) from Hevea brasiliensis [Hevea brasiliensis],4MST_B Crystal Structure of a putative catalytic domain of a chitinase-like protein (HbCLP1) from Hevea brasiliensis [Hevea brasiliensis]

Endochitinase 2 (Fragment) OS=Solanum tuberosum OX=4113 GN=CHTB2 PE=2 SV=1

Chitinase 12 OS=Oryza sativa subsp. japonica OX=39947 GN=Cht12 PE=2 SV=2

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

Endochitinase 3 (Fragment) OS=Solanum tuberosum OX=4113 GN=CHTB3 PE=2 SV=1

Basic endochitinase OS=Vitis vinifera OX=29760 GN=CHIT1B PE=2 SV=1