2DQX

mutant beta-amylase (W55R) from soy bean


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Kinetic and structural analysis of enzyme sliding on a substrate: multiple attack in beta-amylase

Ishikawa, K.Nakatani, H.Katsuya, Y.Fukazawa, C.

(2007) Biochemistry 46: 792-798

  • DOI: 10.1021/bi061605w

  • PubMed Abstract: 
  • Beta-amylase (EC 3.2.1.2) is starch-hydrolyzing exo-type enzyme that can catalyze the successive liberation of beta-maltose from the nonreducing ends of alpha-1,4-linked glucopyranosyl polymers. There is a well-known phenomenon called multiple or rep ...

    Beta-amylase (EC 3.2.1.2) is starch-hydrolyzing exo-type enzyme that can catalyze the successive liberation of beta-maltose from the nonreducing ends of alpha-1,4-linked glucopyranosyl polymers. There is a well-known phenomenon called multiple or repetitive attack where the enzyme releases several maltose molecules in a single enzyme-substrate complex. In order to understand it further, we examined the beta-amylase-catalyzed reaction using maltooligosaccharides. The Monte Carlo method was applied for simulation of the beta-amylase-catalyzed reaction including the multiple attack mechanism. Through site-directed mutagenesis, we have successfully prepared a mutant enzyme which may be simulated as a multiple attack action reduced one with retaining significant hydrolytic activity. From the results of X-ray structure analysis of the mutant enzyme, it was clarified that one carboxyl residue plays a very important role in the multiple attack. The multiple attack action needs the force of enzyme sliding on the substrate. In addition, it is important for the multiple attack that the enzyme and substrate have the characteristics of a stable productive substrate-enzyme complex through a hydrogen bond between the nonreducing end of the substrate and the carboxyl residue of the enzyme.


    Organizational Affiliation

    National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan. kazu-ishikawa@aist.go.jp




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Beta-amylase
A
495Glycine maxEC: 3.2.1.2
Find proteins for Q42795 (Glycine max)
Go to UniProtKB:  Q42795
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.206 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 85.042α = 90.00
b = 85.042β = 90.00
c = 145.083γ = 120.00
Software Package:
Software NamePurpose
CNSrefinement
CrystalCleardata reduction
SCALEPACKdata scaling
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2006-06-01 
  • Released Date: 2007-05-08 
  • Deposition Author(s): Ishikawa, K.

Revision History 

  • Version 1.0: 2007-05-08
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance