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 
  • R-Value Observed: 0.157 

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Ligand Structure Quality Assessment 


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, 1EQC

  • 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 sequence variations, share a common mechanism and are characterised by possessing eight invariant residues making up the active site ...

    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:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
EXO-(B)-(1,3)-GLUCANASEA394Candida albicansMutation(s): 0 
EC: 3.2.1.58 (PDB Primary Data), 2.4.1 (UniProt)
UniProt
Find proteins for P29717 (Candida albicans (strain SC5314 / ATCC MYA-2876))
Explore P29717 
Go to UniProtKB:  P29717
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP29717
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CTS
Query on CTS

Download Ideal Coordinates CCD File 
B [auth A]CASTANOSPERMINE
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 
  • R-Value Observed: 0.157 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.03α = 90
b = 65.12β = 90
c = 97.04γ = 90
Software Package:
Software NamePurpose
ROTAVATAdata reduction
REFMACrefinement
CCP4data scaling
ROTAVATAdata scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

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