2PYG

Azotobacter vinelandii Mannuronan C-5 epimerase AlgE4 A-module


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.194 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural and Mutational Characterization of the Catalytic A-module of the Mannuronan C-5-epimerase AlgE4 from Azotobacter vinelandii.

Rozeboom, H.J.Bjerkan, T.M.Kalk, K.H.Ertesvag, H.Holtan, S.Aachmann, F.L.Valla, S.Dijkstra, B.W.

(2008) J Biol Chem 283: 23819-23828

  • DOI: 10.1074/jbc.M804119200
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Alginate is a family of linear copolymers of (1-->4)-linked beta-d-mannuronic acid and its C-5 epimer alpha-l-guluronic acid. The polymer is first produced as polymannuronic acid and the guluronic acid residues are then introduced at the polymer leve ...

    Alginate is a family of linear copolymers of (1-->4)-linked beta-d-mannuronic acid and its C-5 epimer alpha-l-guluronic acid. The polymer is first produced as polymannuronic acid and the guluronic acid residues are then introduced at the polymer level by mannuronan C-5-epimerases. The structure of the catalytic A-module of the Azotobacter vinelandii mannuronan C-5-epimerase AlgE4 has been determined by x-ray crystallography at 2.1-A resolution. AlgE4A folds into a right-handed parallel beta-helix structure originally found in pectate lyase C and subsequently in several polysaccharide lyases and hydrolases. The beta-helix is composed of four parallel beta-sheets, comprising 12 complete turns, and has an amphipathic alpha-helix near the N terminus. The catalytic site is positioned in a positively charged cleft formed by loops extending from the surface encompassing Asp(152), an amino acid previously shown to be important for the reaction. Site-directed mutagenesis further implicates Tyr(149), His(154), and Asp(178) as being essential for activity. Tyr(149) probably acts as the proton acceptor, whereas His(154) is the proton donor in the epimerization reaction.


    Organizational Affiliation

    Laboratory of Biophysical Chemistry, GBB, University of Groningen, Nijenborgh 4, Groningen, The Netherlands.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Poly(beta-D-mannuronate) C5 epimerase 4A, B377N/AMutation(s): 0 
Gene Names: algE4
EC: 5.1.3
Find proteins for Q44493 (Azotobacter vinelandii)
Explore Q44493 
Go to UniProtKB:  Q44493
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download CCD File 
A
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-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: 2.10 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.194 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 173.953α = 90
b = 121.346β = 90
c = 44.715γ = 90
Software Package:
Software NamePurpose
CNSrefinement
PDB_EXTRACTdata extraction
DENZOdata reduction
SCALEPACKdata scaling
SOLVEphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-05-27
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Non-polymer description, Version format compliance