1EQC

EXO-B-(1,3)-GLUCANASE FROM CANDIDA ALBICANS IN COMPLEX WITH CASTANOSPERMINE AT 1.85 A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.186 
  • R-Value Work: 0.156 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

The structure of the exo-beta-(1,3)-glucanase from Candida albicans in native and bound forms: relationship between a pocket and groove in family 5 glycosyl hydrolases.

Cutfield, S.M.Davies, G.J.Murshudov, G.Anderson, B.F.Moody, P.C.E.Sullivan, P.A.Cutfield, J.F.

(1999) J.Mol.Biol. 294: 771-783

  • DOI: 10.1006/jmbi.1999.3287
  • Primary Citation of Related Structures:  1CZ1
  • Also Cited By: 2PB1, 2PBO, 2PC8

  • PubMed Abstract: 
  • A group of fungal exo-beta-(1,3)-glucanases, including that from the human pathogen Candida albicans (Exg), belong to glycosyl hydrolase family 5 that also includes many bacterial cellulases (endo-beta-1, 4-glucanases). Family members, despite wide s ...

    A group of fungal exo-beta-(1,3)-glucanases, including that from the human pathogen Candida albicans (Exg), belong to glycosyl hydrolase family 5 that also includes many bacterial cellulases (endo-beta-1, 4-glucanases). Family members, despite wide sequence variations, share a common mechanism and are characterised by possessing eight invariant residues making up the active site. These include two glutamate residues acting as nucleophile and acid/base, respectively. Exg is an abundant secreted enzyme possessing both hydrolase and transferase activity consistent with a role in cell wall glucan metabolism and possibly morphogenesis. The structures of Exg in both free and inhibited forms have been determined to 1.9 A resolution. A distorted (beta/alpha)8 barrel structure accommodates an active site which is located within a deep pocket, formed when extended loop regions close off a cellulase-like groove. Structural analysis of a covalently bound mechanism-based inhibitor (2-fluoroglucosylpyranoside) and of a transition-state analogue (castanospermine) has identified the binding interactions at the -1 glucose binding site. In particular the carboxylate of Glu27 serves a dominant hydrogen-bonding role. Access by a 1,3-glucan chain to the pocket in Exg can be understood in terms of a change in conformation of the terminal glucose residue from chair to twisted boat. The geometry of the pocket is not, however, well suited for cleavage of 1,4-glycosidic linkages. A second glucose site was identified at the entrance to the pocket, sandwiched between two antiparallel phenylalanine side-chains. This aromatic entrance-way must not only direct substrate into the pocket but also may act as a clamp for an acceptor molecule participating in the transfer reaction.


    Organizational Affiliation

    Biochemistry Department School of Medical Sciences, University of Otago, Dunedin, New Zealand.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
EXO-(B)-(1,3)-GLUCANASE
A
394Candida albicans (strain SC5314 / ATCC MYA-2876)Gene Names: XOG1 (EXG, EXG1, XOG)
EC: 3.2.1.58, 2.4.1.-
Find proteins for P29717 (Candida albicans (strain SC5314 / ATCC MYA-2876))
Go to UniProtKB:  P29717
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CTS
Query on CTS

Download SDF File 
Download CCD File 
A
CASTANOSPERMINE
(1S,6S,7R,8R,8AR)-1,6,7,8-TETRAHYDROXYINDOLIZIDINE
C8 H15 N O4
JDVVGAQPNNXQDW-TVNFTVLESA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.186 
  • R-Value Work: 0.156 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 60.030α = 90.00
b = 65.120β = 90.00
c = 97.040γ = 90.00
Software Package:
Software NamePurpose
ROTAVATAdata scaling
CCP4data scaling
REFMACrefinement
ROTAVATAdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-10-03
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Refinement description