2Y5E

BARLEY LIMIT DEXTRINASE IN COMPLEX WITH ALPHA-CYCLODEXTRIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.49 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.175 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal Structure of an Essential Enzyme in Seed Starch Degradation: Barley Limit Dextrinase in Complex with Cyclodextrins.

Vester-Christensen, M.B.Abou Hachem, M.Svensson, B.Henriksen, A.

(2010) J.Mol.Biol. 403: 739

  • DOI: 10.1016/j.jmb.2010.09.031
  • Primary Citation of Related Structures:  2Y4S
  • Also Cited By: 4AIO

  • PubMed Abstract: 
  • Barley limit dextrinase [Hordeum vulgare limit dextrinase (HvLD)] catalyzes the hydrolysis of α-1,6 glucosidic linkages in limit dextrins. This activity plays a role in starch degradation during germination and presumably in starch biosynthesis durin ...

    Barley limit dextrinase [Hordeum vulgare limit dextrinase (HvLD)] catalyzes the hydrolysis of α-1,6 glucosidic linkages in limit dextrins. This activity plays a role in starch degradation during germination and presumably in starch biosynthesis during grain filling. The crystal structures of HvLD in complex with the competitive inhibitors α-cyclodextrin (CD) and β-CD are solved and refined to 2.5 Å and 2.1 Å, respectively, and are the first structures of a limit dextrinase. HvLD belongs to glycoside hydrolase 13 family and is composed of four domains: an immunoglobulin-like N-terminal eight-stranded β-sandwich domain, a six-stranded β-sandwich domain belonging to the carbohydrate binding module 48 family, a catalytic (β/α)(8)-like barrel domain that lacks α-helix 5, and a C-terminal eight-stranded β-sandwich domain of unknown function. The CDs are bound at the active site occupying carbohydrate binding subsites +1 and +2. A glycerol and three water molecules mimic a glucose residue at subsite -1, thereby identifying residues involved in catalysis. The bulky Met440, a unique residue at its position among α-1,6 acting enzymes, obstructs subsite -4. The steric hindrance observed is proposed to affect substrate specificity and to cause a low activity of HvLD towards amylopectin. An extended loop (Asp513-Asn520) between β5 and β6 of the catalytic domain also seems to influence substrate specificity and to give HvLD a higher affinity for α-CD than pullulanases. The crystal structures additionally provide new insight into cation sites and the concerted action of the battery of hydrolytic enzymes in starch degradation.


    Related Citations: 
    • Secretory Expression of Functional Barley Limit Dextrinase by Pichia Pastoris Using High Cell- Density Fermentation.
      Vester-Christensen, M.B.,Hachem, M.A.,Naested, H.,Svensson, B.
      (2010) Protein Expr.Purif. 69: 112


    Organizational Affiliation

    Enzyme and Protein Chemistry, Department of Systems Biology, Søltofts Plads, Building 224, Technical University of Denmark, Kgs. Lyngby, Denmark.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
LIMIT DEXTRINASE
A
884Hordeum vulgareGene Names: HvLD99
Find proteins for O48541 (Hordeum vulgare)
Go to UniProtKB:  O48541
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
IOD
Query on IOD

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Download CCD File 
A
IODIDE ION
I
XMBWDFGMSWQBCA-UHFFFAOYSA-M
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

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Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
ACX
Query on ACX

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Download CCD File 
A
ALPHA-CYCLODEXTRIN (CYCLOHEXA-AMYLOSE)
C36 H60 O30
HFHDHCJBZVLPGP-RWMJIURBSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.49 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.175 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 174.840α = 90.00
b = 85.610β = 96.83
c = 61.120γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
MOSFLMdata reduction
PHASERphasing
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-01-26
    Type: Initial release
  • Version 1.1: 2012-11-21
    Type: Database references, Non-polymer description
  • Version 1.2: 2018-01-17
    Type: Data collection