IPR004867
Chitobiase C-terminal domain
InterPro entry
Short name | CHB_C_dom |
Overlapping homologous superfamilies |
Description
E or "early" set domains are associated with the catalytic domain of chitobiase and beta-hexosaminidases (
3.2.1.52) at the C terminus. Chitobiase digests the beta, 1-4 glycosidic bonds of the N-acetylglucosamine (NAG) oligomers found in chitin, an important structural element of fungal cell wall and arthropod exoskeletons. It is thought to proceed through an acid-base reaction mechanism, in which one protein carboxylate acts as the catalytic acid, while the nucleophile is the polar acetamido group of the sugar in a substrate-assisted reaction with retention of the anomeric configuration
[1]. The C terminus of chitobiase is composed of a β sandwich structure
[2] and may be related to the immunoglobulin and/or fibronectin type III superfamilies. E set domains are associated with different types of catalytic domains at either the N-terminal or C-terminal end and may be involved in homodimeric/tetrameric/dodecameric interactions.
References
1.Structures of chitobiase mutants complexed with the substrate Di-N-acetyl-d-glucosamine: the catalytic role of the conserved acidic pair, aspartate 539 and glutamate 540. Prag G, Papanikolau Y, Tavlas G, Vorgias CE, Petratos K, Oppenheim AB. J. Mol. Biol. 300, 611-7, (2000). View articlePMID: 10884356
2.Bacterial chitobiase structure provides insight into catalytic mechanism and the basis of Tay-Sachs disease. Tews I, Perrakis A, Oppenheim A, Dauter Z, Wilson KS, Vorgias CE. Nat. Struct. Biol. 3, 638-48, (1996). View articlePMID: 8673609