3A6O

Crystal structure of Thermoactinomyces vulgaris R-47 alpha-amylase 2/acarbose complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.164 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Complex structures of Thermoactinomyces vulgaris R-47 alpha-amylase 2 with acarbose and cyclodextrins demonstrate the multiple substrate recognition mechanism

Ohtaki, A.Mizuno, M.Tonozuka, T.Sakano, Y.Kamitori, S.

(2004) J Biol Chem 279: 31033-31040

  • DOI: 10.1074/jbc.M404311200
  • Primary Citation of Related Structures:  
    3A6O, 1VFU, 1VFO, 1VFM

  • PubMed Abstract: 
  • Thermoactinomyces vulgaris R-47 alpha-amylase 2 (TVAII) has the unique ability to hydrolyze cyclodextrins (CDs), with various sized cavities, as well as starch. To understand the relationship between structure and substrate specificity, x-ray structu ...

    Thermoactinomyces vulgaris R-47 alpha-amylase 2 (TVAII) has the unique ability to hydrolyze cyclodextrins (CDs), with various sized cavities, as well as starch. To understand the relationship between structure and substrate specificity, x-ray structures of a TVAII-acarbose complex and inactive mutant TVAII (D325N/D421N)/alpha-, beta- and gamma-CDs complexes were determined at resolutions of 2.9, 2.9, 2.8, and 3.1 A, respectively. In all complexes, the interactions between ligands and enzymes at subsites -1, -2, and -3 were almost the same, but striking differences in the catalytic site structure were found at subsites +1 and +2, where Trp(356) and Tyr(374) changed the conformation of the side chain depending on the structure and size of the ligands. Trp(356) and Tyr(374) are thought to be responsible for the multiple substrate-recognition mechanism of TVAII, providing the unique substrate specificity. In the beta-CD complex, the beta-CD maintains a regular conical structure, making it difficult for Glu(354) to protonate the O-4 atom at the hydrolyzing site as a previously proposed hydrolyzing mechanism of alpha-amylase. From the x-ray structures, it is suggested that the protonation of the O-4 atom is possibly carried out via a hydrogen atom of the inter-glucose hydrogen bond at the hydrolyzing site.


    Organizational Affiliation

    Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Neopullulanase 2AB585Thermoactinomyces vulgarisMutation(s): 0 
Gene Names: tvaII
EC: 3.2.1.135
Find proteins for Q08751 (Thermoactinomyces vulgaris)
Explore Q08751 
Go to UniProtKB:  Q08751
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ARE
Query on ARE

Download CCD File 
A, B
ACARBOSE DERIVED PENTASACCHARIDE
C31 H53 N O23
JUCZMZWYUIRMPL-NPPSNIQKSA-N
 Ligand Interaction
CA
Query on CA

Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.164 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 114.599α = 90
b = 119.258β = 90
c = 113.007γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
CNSrefinement
REFMACrefinement
PROCESSdata reduction
SCALAdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-09-22
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance