PDBsum entry 4xwl

Hydrolase

PDB id: 4xwl

Contents

Protein chain

634 a.a.

Ligands

PEG ×5

PG4 ×2

P33

PGE ×4

1PE

EDO ×8

SO4

Metals

_CA

Waters ×472

PDB id:

4xwl

Name:

Hydrolase

Title:

Catalytic domain of clostridium cellulovorans exgs

Structure:

Exoglucanase s. Chain: a. Fragment: catalytic domain, unp residues 32-674. Engineered: yes

Source:

Clostridium cellulovorans. Organism_taxid: 1493. Gene: exgs. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.05Å R-factor: 0.143 R-free: 0.174

Authors:

Y.-C.Liaw

Key ref:

L.C.Tsai et al. (2015). Structures of exoglucanase from Clostridium cellulovorans: cellotetraose binding and cleavage. Acta Crystallogr F Struct Biol Commun, 71, 1264-1272. PubMed id: 26457517 DOI: 10.1107/S2053230X15015915

Date:

29-Jan-15 Release date: 28-Oct-15

Supersedes:

4kih

Protein chain

O65986  (O65986_CLOCL) -  Exoglucanase S from Clostridium cellulovorans

Seq: 727 a.a.

Struc: 634 a.a.

Enzyme reactions

• Enzyme class: E.C.3.2.1.91 - cellulose 1,4-beta-cellobiosidase (non-reducing end).
• Reaction: Hydrolysis of 1,4-beta-D-glucosidic linkages in cellulose and cellotetraose, releasing cellobiose from the non-reducing ends of the chains.

DOI no: 10.1107/S2053230X15015915

Acta Crystallogr F Struct Biol Commun 71:1264-1272 (2015)

PubMed id: 26457517

Structures of exoglucanase from Clostridium cellulovorans: cellotetraose binding and cleavage.

L.C.Tsai, I.Amiraslanov, H.R.Chen, Y.W.Chen, H.L.Lee, P.H.Liang, Y.C.Liaw.

ABSTRACT

Exoglucanase/cellobiohydrolase (EC 3.2.1.176) hydrolyzes a β-1,4-glycosidic bond from the reducing end of cellulose and releases cellobiose as the major product. Three complex crystal structures of the glycosyl hydrolase 48 (GH48) cellobiohydrolase S (ExgS) from Clostridium cellulovorans with cellobiose, cellotetraose and triethylene glycol molecules were solved. The product cellobiose occupies subsites +1 and +2 in the open active-site cleft of the enzyme-cellotetraose complex structure, indicating an enzymatic hydrolysis function. Moreover, three triethylene glycol molecules and one pentaethylene glycol molecule are located at active-site subsites -2 to -6 in the structure of the ExgS-triethylene glycol complex shown here. Modelling of glucose into subsite -1 in the active site of the ExgS-cellobiose structure revealed that Glu50 acts as a proton donor and Asp222 plays a nucleophilic role.