1TR1

CRYSTAL STRUCTURE OF E96K MUTATED BETA-GLUCOSIDASE A FROM BACILLUS POLYMYXA, AN ENZYME WITH INCREASED THERMORESISTANCE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.210 

wwPDB Validation   3D Report Full Report


This is version 1.5 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:  
    1TR1, 1BGG, 1BGA

  • 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 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 ...

    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: 
    • Amino Acid Substitutions Enhancing Thermostability of Bacillus Polymyxa Beta-Glucosidase A
      Lopez-Camacho, C., Salgado, J., Lequerica, J.L., Madarro, A., Ballestar, E., Franco, L., Polaina, J.
      (1996) Biochem J 314: 833

    Organizational Affiliation

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



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
BETA-GLUCOSIDASE AABCD447Paenibacillus polymyxaMutation(s): 1 
Gene Names: bglA
EC: 3.2.1.21
Find proteins for P22073 (Paenibacillus polymyxa)
Explore P22073 
Go to UniProtKB:  P22073
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download CCD File 
A, B, C, D
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.210 
  • Space Group: P 42 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 205.03α = 90
b = 205.03β = 90
c = 155.43γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
XDSdata reduction
XSCALAdata scaling
CCP4data scaling
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-04-20
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.3: 2018-03-14
    Changes: Database references, Other
  • Version 1.4: 2018-04-04
    Changes: Data collection
  • Version 1.5: 2018-04-11
    Changes: Data collection