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Glycoside Hydrolase Family 138
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- Author: ^^^Didier Ndeh^^^
- Responsible Curator: ^^^Harry Gilbert^^^
| Glycoside Hydrolase Family GH138 | |
| Clan | none |
| Mechanism | unknown |
| Active site residues | unknown |
| CAZy DB link | |
| https://www.cazy.org/GH138.html | |
Substrate specificities
Glycoside hydrolases of family 138 (GH138) exhibit α-D-galacturonidase activity. This is based on data from the characterisation of the founding member of the family BT0997 encoded by the prominent human gut bacterium B. thetaiotaomicron [1]. BT0997 hydrolyses a fragment (GalA-α1,2(GalA-β1,3)(2MeXyl-α1,3-Fuc-α1,4)Rha-α1,3-Api) of Chain A from the pectic polysaccharide Rhamnogalacturonan II, producing D-galacturonic acid and the resulting oligosaccharide GalA-β1,3(2MeXyl-α1,3Fuc-α1,4)Rha-α1,3Api [1], demonstrating that BT0997 cleaved the D-Gal-α1,2-Rhap linkage. Several members of this family have been identified in gut and environmental bacteria with a majority of the encoding microbes belonging to the Bacteroidetes phylum [2, 3]. This phylum is highly represented in human gut microbial populations [4].
Kinetics and Mechanism
The kinetic mechanism for this family has not been reported
Catalytic Residues
The catalytic residues for this family have not yet been identified.
Three-dimensional structures
No 3D structure for a member of this family has been currently reported
Family Firsts
- First stereochemistry determination
- Currently unknown.
- First catalytic nucleophile identification
- Currently unknown.
- First general acid/base residue identification
- Currently unknown.
- First 3-D structure
- Currently unknown.
References
- 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 |
- Lombard V, Golaconda Ramulu H, Drula E, Coutinho PM, and Henrissat B. (2014). The carbohydrate-active enzymes database (CAZy) in 2013. Nucleic Acids Res. 2014;42(Database issue):D490-5. DOI:10.1093/nar/gkt1178 |
- Cantarel BL, Coutinho PM, Rancurel C, Bernard T, Lombard V, and Henrissat B. (2009). The Carbohydrate-Active EnZymes database (CAZy): an expert resource for Glycogenomics. Nucleic Acids Res. 2009;37(Database issue):D233-8. DOI:10.1093/nar/gkn663 |
- Qin J, Li R, Raes J, Arumugam M, Burgdorf KS, Manichanh C, Nielsen T, Pons N, Levenez F, Yamada T, Mende DR, Li J, Xu J, Li S, Li D, Cao J, Wang B, Liang H, Zheng H, Xie Y, Tap J, Lepage P, Bertalan M, Batto JM, Hansen T, Le Paslier D, Linneberg A, Nielsen HB, Pelletier E, Renault P, Sicheritz-Ponten T, Turner K, Zhu H, Yu C, Li S, Jian M, Zhou Y, Li Y, Zhang X, Li S, Qin N, Yang H, Wang J, Brunak S, Doré J, Guarner F, Kristiansen K, Pedersen O, Parkhill J, Weissenbach J, MetaHIT Consortium, Bork P, Ehrlich SD, and Wang J. (2010). A human gut microbial gene catalogue established by metagenomic sequencing. Nature. 2010;464(7285):59-65. DOI:10.1038/nature08821 |