PDBsum entry: 2iw0

Hydrolase

PDB-id: 2iw0

Contents

Description

Header details

Header records

References

PROCHECK

Protein chain

226 a.a. *

Ligands

ACT ×3

PO4

Metal ions

_ZN

_CL

Waters ×175

* Residue conservation analysis

Tools

Clefts Calculation

PDB id:

2iw0

Name:

Hydrolase

Title:

Structure of the chitin deacetylase from the fungal pathogen colletotrichum lindemuthianum

Structure:

Chitin deacetylase. Chain: a. Engineered: yes

Source:

Colletotrichum lindemuthianum. Glomerella lindemuthiana. Organism_taxid: 290576. Strain: ups9. Expressed in: pichia pastoris. Expression_system_taxid: 4922.

UniProt:

Q6DWK3 (Q6DWK3_COLLN)

Seq:

248 a.a.

Struc:

226 a.a.*

Key:

PfamA domain

Secondary structure

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme class:

E.C.3.5.1.41   [IntEnz]   [ExPASy]   [KEGG]   [BRENDA]

Reaction:

Chitin + H₂O = chitosan + acetate (see diagram below)

Resolution:

1.81Å

R-factor:

0.174

R-free:

0.215

Authors:

D.E.Blair,O.Hekmat,A.W.Schuttelkopf,B.Shrestha,K.Tokuyasu, S.G.Withers,D.M.F.Van Aalten

Key ref:

D.E.Blair et al. (2006). Structure and mechanism of chitin deacetylase from the fungal pathogen Colletotrichum lindemuthianum.. Biochemistry, 45, 9416-9426. [PubMed id: 16878976] [DOI: 10.1021/bi0606694]

Date:

23-Jun-06

Release date:

04-Jul-06

Quick_links

Procheck

Clefts

Surface

Key reference

DOI no: 10.1021/bi0606694

Biochemistry 45:9416-9426 (2006)

PubMed id: 16878976

Structure and mechanism of chitin deacetylase from the fungal pathogen Colletotrichum lindemuthianum.

D.E.Blair, O.Hekmat, A.W.Schüttelkopf, B.Shrestha, K.Tokuyasu, S.G.Withers, D.M.van Aalten.

ABSTRACT

The fungal pathogen Colletotrichum lindemuthianum secretes an endo-chitin de-N-acetylase (ClCDA) to modify exposed hyphal chitin during penetration and infection of plants. Although a significant amount of biochemical data is available on fungal chitin de-N-acetylases, no structural data exist. Here we describe the 1.8 A crystal structure of a ClCDA product complex and the analysis of the reaction mechanism using Hammett linear free energy relationships, subsite probing, and atomic absorption spectroscopy studies. The structural data in combination with biochemical data reveal that ClCDA consists of a single domain encompassing a mononuclear metalloenzyme which employs a conserved His-His-Asp zinc-binding triad closely associated with the conserved catalytic base (aspartic acid) and acid (histidine) to carry out acid/base catalysis. The data presented here indicate that ClCDA possesses a highly conserved substrate-binding groove, with subtle alterations that influence substrate specificity and subsite affinity. Strikingly, the structure also shows that the hexahistidine purification tag appears to form a tight interaction with the active site groove. The enzyme requires occupancy of at least the 0 and +1 subsites by (GlcNAc)(2) for activity and proceeds through a tetrahedral oxyanion intermediate.