Glycoside Hydrolase Family 116

This page is currently under construction. This means that the Responsible Curator has deemed that the page's content is not quite up to CAZypedia's standards for full public consumption. All information should be considered to be under revision and may be subject to major changes.

• Author: ^^^Beatrice Cobucci-Ponzano^^^
• Responsible Curator: ^^^Marco Moracci^^^

---

Glycoside Hydrolase Family GH116
Clan	GH-x
Mechanism	retaining
Active site residues	known
CAZy DB link
http://www.cazy.org/GH116.html

Substrate specificities

This family of glycoside hydrolases was recently discovered characterising a new β-glucosidase from the hyperthermophilic archaeon Sulfolobus solfataricus [1]. This enzyme is distantly related to the human non-lysosomal bile acid β-glucosidase GBA2, also known as glucocerebrosidase [2]. GH116 contains acid β-glucosidase (EC 3.2.1.45), β-glucosidase (EC 3.2.1.21) and β-xylosidase (EC 3.2.1.37) from the three domains of life.

Kinetics and Mechanism

The enzymes of this family are retaining glycoside hydrolases, and follow the classical Koshland double-displacement mechanism [3]. The stereochemistry of hydrolysis has been demonstrated by NMR using 4NP-β-Xyl as the substrate and S. solfataricus SSO1353 as the enzyme [1].

Catalytic Residues

The catalytic residues were identified in the S. solfataricus β-glucosidase [1]. The catalytic nucleophile was identified as Glu335 in the sequence AIYEAP through trapping of the 2,4-deoxy-2-fluoroglucosyl-enzyme intermediate and MS/MS analysis. The general acid/base catalyst role was assigned to Asp462 through mechanistic analysis, which included azide rescue experiments, of a mutant at that position.

Three-dimensional structures

Content is to be added here.

Family Firsts

First stereochemistry determination

Cite some reference here, with a short (1-2 sentence) explanation [4].

First catalytic nucleophile identification

Cite some reference here, with a short (1-2 sentence) explanation [5].

First general acid/base residue identification

Cite some reference here, with a short (1-2 sentence) explanation [6].

First 3-D structure

Cite some reference here, with a short (1-2 sentence) explanation [7].

References

1. Cobucci-Ponzano B, Aurilia V, Riccio G, Henrissat B, Coutinho PM, Strazzulli A, Padula A, Corsaro MM, Pieretti G, Pocsfalvi G, Fiume I, Cannio R, Rossi M, and Moracci M. (2010). A new archaeal beta-glycosidase from Sulfolobus solfataricus: seeding a novel retaining beta-glycan-specific glycoside hydrolase family along with the human non-lysosomal glucosylceramidase GBA2. J Biol Chem. 2010;285(27):20691-703. DOI:10.1074/jbc.M109.086470 |
2. Boot RG, Verhoek M, Donker-Koopman W, Strijland A, van Marle J, Overkleeft HS, Wennekes T, and Aerts JM. (2007). Identification of the non-lysosomal glucosylceramidase as beta-glucosidase 2. J Biol Chem. 2007;282(2):1305-12. DOI:10.1074/jbc.M610544200 |

3. Koshland DE Jr: Stereochemistry and the mechanism of enzyme reactions. Biol Rev 1953, 28:416-436.