Glycoside Hydrolase Family 82

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.

• Authors: ^^^Mirjam Czjzek^^^ and ^^^Gurvan Michel^^^
• Responsible Curator: ^^^Mirjam Czjzek^^^

---

Glycoside Hydrolase Family GH82
Clan	none
Mechanism	inverting
Active site residues	not known
CAZy DB link
http://www.cazy.org/fam/GH82.html

Substrate specificities

The two known members of glycoside hydrolase family 82 enzymes cleave the β-1,4 galactosidic bond of the marine algal polysaccharide iota-carrageenan [1] yielding products of the neocarrabiose series.

Kinetics and Mechanism

Family 82 enzymes are inverting enzymes, as first shown by NMR [1] on the iota-carrageenase from Alteromonas fortis.

Catalytic Residues

From structural analysis predicted to be two out of the three candidate amino acids Glu245, Asp247 or Glu310 in the A. fortis iota-carrageenase [2].

Three-dimensional structures

To date, a crystal structure has only been determined for the iota-carrageenase from A. fortis [2]. The crystal structure of a product complex has shed light on the existance of domain movement of domain A that is closed around the oligo-carrageenan in the complexed form and open in the uncomplexed enzyme [3].

Family Firsts

First sequence identification and family creation

iota-carrageenase sequences have been first reported for enzymes from A. fortis and Z. galactanivorans [1].

First sterochemistry determination

GH82 enzymes are inverting as shown by NMR [1].

First general acid residue identification

not determined yet.

First general base residue identification

not determined yet.

First 3-D structure

iota-carrageenase from A. fortis [2]. The structure belongs to the β-helix fold (PDB 1h80 and PDB 1ktw).

References

1. Barbeyron T, Michel G, Potin P, Henrissat B, and Kloareg B. (2000). iota-Carrageenases constitute a novel family of glycoside hydrolases, unrelated to that of kappa-carrageenases. J Biol Chem. 2000;275(45):35499-505. DOI:10.1074/jbc.M003404200 |
2. Michel G, Chantalat L, Fanchon E, Henrissat B, Kloareg B, and Dideberg O. (2001). The iota-carrageenase of Alteromonas fortis. A beta-helix fold-containing enzyme for the degradation of a highly polyanionic polysaccharide. J Biol Chem. 2001;276(43):40202-9. DOI:10.1074/jbc.M100670200 |
3. Michel G, Helbert W, Kahn R, Dideberg O, and Kloareg B. (2003). The structural bases of the processive degradation of iota-carrageenan, a main cell wall polysaccharide of red algae. J Mol Biol. 2003;334(3):421-33. DOI:10.1016/j.jmb.2003.09.056 |