Table 1.
Glycoside hydrolase (GH) families including enzymes with EC 3.2.1.8 (endo-1,4-β-xylanase) specificity and/or other specificity for endo-activity on substituted xylans (from www.cazy.org, March 2016).
|
Clan
(overall fold) |
Family
(number of characterized enzymes) |
Mechanism |
Subfamily
(number of characterized enzymes) |
EC number | Number of characterized endo-xylanases | Number of structure determined endo-xylanases |
|---|---|---|---|---|---|---|
| GH-A ((αβ)8) |
GH5 (538) |
retaining | subfamily 1-53 | |||
| subfamily 4 (95) |
EC 3.2.1.8/3.2.1.4 (cellulase) | 4(bifunctional) | 1 | |||
| subfamily 21 (4) |
EC 3.2.1.8 | 4 | 0 | |||
| subfamily 25 (11) |
1(bifunctional) | 1 | ||||
| subfamily 34 (1) |
EC 3.2.1.- (arabinoxylan specific) | 1 | 1 | |||
| GH10 (342) |
retaining | - | EC 3.2.1.8 | >300 | 38 | |
| GH30 (34) |
retaining | subfamily 1-8 | ||||
| subfamily 8 (15) |
enzymes acting on xylan/glucuronoxylan | |||||
| EC 3.2.1.8 | 10 | 1 | ||||
| EC 3.2.1.136 (glucuronoarabinoxylan endo-1,4-β-xylanase) | 2 | 1 | ||||
| EC 3.2.1.8/3.2.1.136 | 3(bifunctional) | 2 | ||||
| GH51 (76) |
retaining | - | GH-family of predominantly arabinofuranosidases EC 3.2.1.8/3.2.1.4 |
1(bifunctional) | 0 | |
| GH-C (β-jelly roll) |
GH11 (270) |
retaining | - | EC 3.2.1.8 | >250 | 29 |
| GH-F (5-fold β-propeller) |
GH43 (139) |
inverting | subfamily 1-37 | GH family of mainly exo-acting enzymes | ||
| subfamily16 | EC 3.2.1.8 | 3 | 0 | |||
| EC 3.2.1.8/3.2.1.55 (arabinofuranosidase) | 2(bifunctional) | 0 | ||||
| subfamily29 | EC 3.2.1.8 | 1 | 0 | |||
| GH-M (α/α)6 |
GH8 (71) |
inverting | - | multi-specific family: | ||
| EC 3.2.1.8 | 8 | 1 | ||||
| EC 3.2.1.156 (oligosaccharide reducing-end xylanase) | 4 | 1 | ||||
| No clan | GH98 (5) |
inverting | - | small GH family with galactosidase and xylanase activities EC 3.2.1.8 |
1 |
0 |