1BGA

BETA-GLUCOSIDASE A FROM BACILLUS POLYMYXA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of beta-glucosidase A from Bacillus polymyxa: insights into the catalytic activity in family 1 glycosyl hydrolases.

Sanz-Aparicio, J.Hermoso, J.A.Martinez-Ripoll, M.Lequerica, J.L.Polaina, J.

(1998) J.Mol.Biol. 275: 491-502

  • DOI: 10.1006/jmbi.1997.1467
  • Primary Citation of Related Structures:  1BGG, 1TR1
  • Also Cited By: 1E4I, 1UYQ

  • PubMed Abstract: 
  • Family 1 glycosyl hydrolases are a very relevant group of enzymes because of the diversity of biological roles in which they are involved, and their generalized occurrence in all sorts of living organisms. The biological plasticity of these enzymes i ...

    Family 1 glycosyl hydrolases are a very relevant group of enzymes because of the diversity of biological roles in which they are involved, and their generalized occurrence in all sorts of living organisms. The biological plasticity of these enzymes is a consequence of the variety of beta-glycosidic substrates that they can hydrolyze: disaccharides such as cellobiose and lactose, phosphorylated disaccharides, cyanogenic glycosides, etc. The crystal structure of BglA, a member of the family, has been determined in the native state and complexed with gluconate ligand, at 2.4 A and 2.3 A resolution, respectively. The subunits of the octameric enzyme display the (alpha/beta)8 barrel structural fold previously reported for other family 1 enzymes. However, significant structural differences have been encountered in the loops surrounding the active-center cavity. These differences make a wide and extended cavity in BglA, which seems to be able to accommodate substrates longer than cellobiose, its natural substrate. Furthermore, a third sub-site is encountered, which might have some connection with the transglycosylating activity associated to this enzyme and its certain activity against beta-1,4 oligosaccharides composed of more than two units of glucose. The particular geometry of the cavity which contains the active center of BglA must therefore account for both, hydrolytic and transglycosylating activities. A potent and well known inhibitor of different glycosidases, D-glucono-1,5-lactone, was used in an attempt to define interactions of the substrate with specific protein residues. Although the lactone has transformed into gluconate under crystallizing conditions, the open species still binds the enzyme, the conformation of its chain mimicking the true inhibitor. From the analysis of the enzyme-ligand hydrogen bonding interactions, a detailed picture of the active center can be drawn, for a family 1 enzyme. In this way, Gln20, His121, Tyr296, Glu405 and Trp406 are identified as determinant residues in the recognition of the substrate. In particular, two bidentate hydrogen bonds made by Gln20 and Glu405, could conform the structural explanation for the ability of most members of the family for displaying both, glucosidase and galactosidase activity.


    Related Citations: 
    • Crystallization and Preliminary X-Ray Diffraction Analysis of a Type I Beta-Glucosidase Encoded by the Bgla Gene of Bacillus Polymyxa
      Sanz-Aparicio, J.,Romero, A.,Martinez-Ripoll, M.,Madarro, A.,Flors, A.,Polaina, J.
      (1994) J.Mol.Biol. 240: 267
    • Purification and Characterization of a Bacillus Polymyxa Beta-Glucosidase Expressed in Escherichia Coli
      Painbeni, E.,Valles, S.,Polaina, J.,Flors, A.
      (1992) J.Bacteriol. 174: 3087


    Organizational Affiliation

    Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física Rocasolano, CSIC, Madrid, Spain.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BETA-GLUCOSIDASE A
A, B, C, D
447Paenibacillus polymyxaGene Names: bglA
EC: 3.2.1.21
Find proteins for P22073 (Paenibacillus polymyxa)
Go to UniProtKB:  P22073
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.200 
  • Space Group: P 42 21 2
Unit Cell:
Length (Å)Angle (°)
a = 205.460α = 90.00
b = 205.460β = 90.00
c = 155.860γ = 90.00
Software Package:
Software NamePurpose
X-PLORmodel building
CCP4data scaling
ROTAVATA)data scaling
X-PLORrefinement
MOSFLMdata reduction
X-PLORphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-04-15
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance