2AJT

Crystal structure of L-Arabinose Isomerase from E.coli


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.220 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Crystal Structure of Escherichia coli L-Arabinose Isomerase (ECAI), The Putative Target of Biological Tagatose Production

Manjasetty, B.A.Chance, M.R.

(2006) J Mol Biol 360: 297-309

  • DOI: https://doi.org/10.1016/j.jmb.2006.04.040
  • Primary Citation of Related Structures:  
    2AJT

  • PubMed Abstract: 

    Escherichia coli L-arabinose isomerase (ECAI; EC 5.3.1.4) catalyzes the isomerization of L-arabinose to L-ribulose in vivo. This enzyme is also of commercial interest as it catalyzes the conversion of D-galactose to D-tagatose in vitro. The crystal structure of ECAI was solved and refined at 2.6 A resolution. The subunit structure of ECAI is organised into three domains: an N-terminal, a central and a C-terminal domain. It forms a crystallographic trimeric architecture in the asymmetric unit. Packing within the crystal suggests the idea that ECAI can form a hexameric assembly. Previous electron microscopic and biochemical studies supports that ECAI is hexameric in solution. A comparison with other known structures reveals that ECAI adopts a protein fold most similar to E. coli fucose isomerase (ECFI) despite very low sequence identity 9.7%. The structural similarity between ECAI and ECFI with regard to number of domains, overall fold, biological assembly, and active site architecture strongly suggests that the enzymes have functional similarities. Further, the crystal structure of ECAI forms a basis for identifying molecular determinants responsible for isomerization of arabinose to ribulose in vivo and galactose to tagatose in vitro.


  • Organizational Affiliation

    New York Structural Genomix Research Consortium, Center for Synchrotron Biosciences, National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
L-arabinose isomerase
A, B, C
500Escherichia coliMutation(s): 0 
Gene Names: araA
EC: 5.3.1.4
UniProt
Find proteins for P08202 (Escherichia coli (strain K12))
Explore P08202 
Go to UniProtKB:  P08202
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP08202
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.220 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 116.539α = 90
b = 116.539β = 90
c = 214.33γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
SHELXDphasing
SOLVEphasing

Structure Validation

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Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2005-08-16
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Derived calculations, Version format compliance
  • Version 1.3: 2021-02-03
    Changes: Structure summary
  • Version 1.4: 2024-02-14
    Changes: Data collection, Database references