Active Site

Glycoside hydrolase family 11, active site 1 (IPR018208)

Short name: GH11_AS_1


The microbial degradation of cellulose and xylans requires several types of enzymes such as endoglucanases (EC:, cellobiohydrolases (EC: (exoglucanases), or xylanases (EC: [PMID: 2252383, PMID: 1886523]. Fungi and bacteria produces a spectrum of cellulolytic enzymes (cellulases) and xylanases which, on the basis of sequence similarities, can be classified into families. One of these families is known as the cellulase family G [PMID: 2806912] or as the glycosyl hydrolases family 11 [PMID: 1747104].

The GH11 domain folds into a jelly-roll shape likened to a partially closed right hand. Several anti-parallel beta-strands bend almost 90deg to produce a substrate-binding groove characteristic of the GH11 domain active sites. Two catalytic Glu residues face each other from opposite sides of the groove. The hydrolysis reaction is believed to follow a double- displacement mechanism, with one Glu residue acting as a general acid/base catalyst and the other as a nucleophile.

This entry represents a conserved region found in these enzymes that is centred on glutamic acid residues. The other conserved region is represented in IPR033119. In Bacillus pumilis xylanase, this site is necessary for catalytic activity [PMID: 1359880].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns