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Glycoside Hydrolase Family 131
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- Author: ^^^Jean-Guy Berrin^^^
- Responsible Curator: ^^^Jean-Guy Berrin^^^
| Glycoside Hydrolase Family GH131 | |
| Clan | GH-x |
| Mechanism | not known |
| Active site residues | not known |
| CAZy DB link | |
| https://www.cazy.org/GH131.html | |
Substrate specificities
This family of glycoside hydrolases comprises only enzymes of fungal origin. Several of these enzymes contain predicted cellulose-binding modules from family CBM1. Only one member (gene Pa_3_10940) has been characterized to date from the coprophilic ascomycete Podospora anserina [1]. This first member is a broad specificity β-glucanase with exo-β-1,3/1,6- and endo-β-1,4-glucanase activity [1].
Kinetics and Mechanism
The Podospora anserina GH131 beta-glucanase displays activity towards a broad range of β-glucan polysaccharides including laminarin, curdlan, pachyman, lichenan, pustulan and also cellulosic derivatives [1]. Analysis of the products released from polysaccharides revealed that this β-glucanase is an exo-acting enzyme on β-(1,3)- and β-(1,6)-linked glucan substrates and an endo-acting enzyme on β-(1,4)-linked glucan substrates. Hydrolysis of short β-(1,3), β-(1,4) and β-(1,3)/β-(1,4) gluco-oligosaccharides confirmed this striking feature and revealed that the enzyme acted in an exo-mode on the non-reducing end of gluco-oligosaccharides.
Catalytic Residues
Not known.
Three-dimensional structures
Only one crystal structure of a glycoside hydrolase family 131 protein from Coprinopsis cinerea is available [2]. The structure of CcGH131A was found to be composed of a β-jelly roll fold and mainly consisted of two β-sheets, sheet-A and sheet-B. Arg96, Glu98, Glu138, and His218 are likely to be catalytically critical residues and it was suggested that the catalytic mechanism of CcGH131A is different from that of typical glycosidases [2].
Family Firsts
- First stereochemistry determination
- No experimental proof.
- First catalytic nucleophile identification
- No experimental proof.
- First general acid/base residue identification
- No experimental proof.
- First 3-D structure
- Coprinopsis cinerea CcGH131A [2].
References
- Lafond M, Navarro D, Haon M, Couturier M, and Berrin JG. (2012). Characterization of a broad-specificity β-glucanase acting on β-(1,3)-, β-(1,4)-, and β-(1,6)-glucans that defines a new glycoside hydrolase family. Appl Environ Microbiol. 2012;78(24):8540-6. DOI:10.1128/AEM.02572-12 |
- Miyazaki T, Yoshida M, Tamura M, Tanaka Y, Umezawa K, Nishikawa A, and Tonozuka T. (2013). Crystal structure of the N-terminal domain of a glycoside hydrolase family 131 protein from Coprinopsis cinerea. FEBS Lett. 2013;587(14):2193-8. DOI:10.1016/j.febslet.2013.05.041 |