| EC |
3.2.1.155 |
| Accepted name: |
xyloglucan-specific exo-β-1,4-glucanase |
| Reaction: |
Hydrolysis of (1→4)-D-glucosidic linkages in xyloglucans so as to successively remove oligosaccharides from the chain end. |
| Other name(s): |
Cel74A |
| Systematic name: |
[(1→6)-α-D-xylo]-(1→4)-β-D-glucan exo-glucohydrolase |
| Comments: |
The enzyme removes XXXG heptasaccharides, XXLG/XLXG octasaccharides and XLLG nonasaccharides from the end of tamarind seed xyloglucan polymers in a processive manner. Hydrolysis occurs at the unsubstituted D-glucopyranose residue in the main backbone. It is not known whether the cleavage takes place at the reducing or non-reducing end of the polymer. Very low activity with β-D-glucans. The enzyme from Chrysosporium lucknowense shifts to an endoglucanase mode when acting on linear substrates without bulky substituents on the polymeric backbone such as barley β-glucan. |
| References: |
| 1. |
Grishutin, S.G., Gusakov, A.V., Markov, A.V., Ustinov, B.B., Semenova, M.V. and Sinitsyn, A.P. Specific xyloglucanases as a new class of polysaccharide-degrading enzymes. Biochim. Biophys. Acta 1674 (2004) 268–281. [PMID: 15541296] |
|
| [EC 3.2.1.155 created 2005, withdrawn at public-review stage, modified and reinstated 2006, modified 2011] |
| |
|
| |
|