Xyloglucan endo-transglycosylase (XET) C-terminus. This family represents the C-terminus (approximately 60 residues) of plant xyloglucan endo-transglycosylase (XET). Xyloglucan is the predominant hemicellulose in the cell walls of most dicotyledons. With cellulose, it forms a network that strengthens the cell wall. XET catalyzes the splitting of xyloglucan chains and the linking of the newly generated reducing end to the non-reducing end of another xyloglucan chain, thereby loosening the cell wall. Note that all family members contain the pfam00722 domain.

lichenase, member of glycosyl hydrolase family 16. Lichenase, also known as 1,3-1,4-beta-glucanase, is a member of glycosyl hydrolase family 16, that specifically cleaves 1,4-beta-D-glucosidic bonds in mixed-linked beta glucans that also contain 1,3-beta-D-glucosidic linkages. Natural substrates of beta-glucanase are beta-glucans from grain endosperm cell walls or lichenan from the Islandic moss, Cetraria islandica. This protein is found not only in bacteria but also in anaerobic fungi. This domain includes two seven-stranded antiparallel beta-sheets that are adjacent to one another forming a compact, jellyroll beta-sandwich structure.

Glycosyl hydrolases family 16.

Probable xyloglucan endotransglucosylase/hydrolase protein; Provisional

Xyloglucan endotransglycosylase, member of glycosyl hydrolase family 16. Xyloglucan endotransglycosylases (XETs) cleave and religate xyloglucan polymers in plant cell walls via a transglycosylation mechanism. Xyloglucan is a soluble hemicellulose with a backbone of beta-1,4-linked glucose units, partially substituted with alpha-1,6-linked xylopyranose branches. It binds noncovalently to cellulose, cross-linking the adjacent cellulose microfibrils, giving it a key structural role as a matrix polymer. Therefore, XET plays an important role in all plant processes that require cell wall remodeling.