Glycoside Hydrolase Family 142

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• Author: Grete Raba
• Responsible Curator: Ana Luis

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Glycoside Hydrolase Family GH142
Clan	GH-x
Mechanism	not known
Active site residues	not known
CAZy DB link
https://www.cazy.org/GH142.html

Substrate specificities

The glycoside hydrolases from GH family 142 have β-L-arabinofuranosidase (EC 3.2.1.185) activity. The first characterized enzyme from GH142 was the C-terminus of BT1020 from Bacteroides thetaiotaomicron [1]. BT1020 C-terminus hydrolyses the β-1,5 linkage between L-arabinofuranosidase and D-DHA at the non-reducing end of rhamnogalacturonan II (RG II) D chain found in pectin.

Kinetics and Mechanism

The kinetics and mechanisms of GH142 family remain to be elucidated.

Catalytic Residues

The β-L-arabinofuranosidase from BT1020 C-terminus contains canonical glycoside hydrolase catalytic apparatus comprising carboxylate residues [1].

Three-dimensional structures

The β-L-arabinofuranosidase from the C-terminus of BT1020 has a (α/α)6-barrel structure [1].

Family Firsts

First stereochemistry determination

Not yet identified.

First catalytic nucleophile identification

BT1020 from Bacteroides thetaiotaomicron [1].

First general acid/base residue identification

Not yet identified.

First 3-D structure

BT1020 from Bacteroides thetaiotaomicron [1].

References

1. Ndeh D, Rogowski A, Cartmell A, Luis AS, Baslé A, Gray J, Venditto I, Briggs J, Zhang X, Labourel A, Terrapon N, Buffetto F, Nepogodiev S, Xiao Y, Field RA, Zhu Y, O'Neil MA, Urbanowicz BR, York WS, Davies GJ, Abbott DW, Ralet MC, Martens EC, Henrissat B, and Gilbert HJ. (2017). Complex pectin metabolism by gut bacteria reveals novel catalytic functions. Nature. 2017;544(7648):65-70. DOI:10.1038/nature21725 |