3WEO

Sugar beet alpha-glucosidase with acarviosyl-maltohexaose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.150 
  • R-Value Work: 0.123 
  • R-Value Observed: 0.124 

wwPDB Validation   3D Report Full Report


This is version 2.0 of the entry. See complete history


Literature

Structural advantage of sugar beet alpha-glucosidase to stabilize the Michaelis complex with long-chain substrate

Tagami, T.Yamashita, K.Okuyama, M.Mori, H.Yao, M.Kimura, A.

(2014) J Biol Chem 290: 1796-1803

  • DOI: 10.1074/jbc.M114.606939
  • Primary Citation of Related Structures:  
    3WEL, 3WEM, 3WEN, 3WEO

  • PubMed Abstract: 
  • The α-glucosidase from sugar beet (SBG) is an exo-type glycosidase. The enzyme has a pocket-shaped active site, but efficiently hydrolyzes longer maltooligosaccharides and soluble starch due to lower Km and higher kcat/Km for such substrates. To obtain structural insights into the mechanism governing its unique substrate specificity, a series of acarviosyl-maltooligosaccharides was employed for steady-state kinetic and structural analyses ...

    The α-glucosidase from sugar beet (SBG) is an exo-type glycosidase. The enzyme has a pocket-shaped active site, but efficiently hydrolyzes longer maltooligosaccharides and soluble starch due to lower Km and higher kcat/Km for such substrates. To obtain structural insights into the mechanism governing its unique substrate specificity, a series of acarviosyl-maltooligosaccharides was employed for steady-state kinetic and structural analyses. The acarviosyl-maltooligosaccharides have a longer maltooligosaccharide moiety compared with the maltose moiety of acarbose, which is known to be the transition state analog of α-glycosidases. The clear correlation obtained between log Ki of the acarviosyl-maltooligosaccharides and log(Km/kcat) for hydrolysis of maltooligosaccharides suggests that the acarviosyl-maltooligosaccharides are transition state mimics. The crystal structure of the enzyme bound with acarviosyl-maltohexaose reveals that substrate binding at a distance from the active site is maintained largely by van der Waals interactions, with the four glucose residues at the reducing terminus of acarviosyl-maltohexaose retaining a left-handed single-helical conformation, as also observed in cycloamyloses and single helical V-amyloses. The kinetic behavior and structural features suggest that the subsite structure suitable for the stable conformation of amylose lowers the Km for long-chain substrates, which in turn is responsible for higher specificity of the longer substrates.


    Organizational Affiliation

    From the Research Faculty of Agriculture, kimura@abs.agr.hokudai.ac.jp.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Alpha-glucosidase A913Beta vulgarisMutation(s): 0 
Gene Names: Agl
EC: 3.2.1.20
Find proteins for L0N7E5 (Beta vulgaris)
Explore L0N7E5 
Go to UniProtKB:  L0N7E5
Protein Feature View
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  • Reference Sequence
Oligosaccharides

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Entity ID: 2
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
alpha-L-fucopyranose-(1-3)-[2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)]2-acetamido-2-deoxy-beta-D-glucopyranose
B
3 N-Glycosylation Oligosaccharides Interaction
Entity ID: 3
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
C
2 N-Glycosylation Oligosaccharides Interaction
Entity ID: 4
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
4,6-dideoxy-4-{[(1S,4R,5S,6S)-4,5,6-trihydroxy-3-(hydroxymethyl)cyclohex-2-en-1-yl]amino}-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose
D
7 N/A N/A Oligosaccharides Interaction
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download Ideal Coordinates CCD File 
A
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
SO4
Query on SO4

Download Ideal Coordinates CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

Download Ideal Coordinates CCD File 
A
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.150 
  • R-Value Work: 0.123 
  • R-Value Observed: 0.124 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 86.166α = 90
b = 99.154β = 90
c = 107.354γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
BSSdata collection
XDSdata reduction
XDSdata scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-07-16
    Type: Initial release
  • Version 1.1: 2014-07-30
    Changes: Other
  • Version 1.2: 2014-12-31
    Changes: Database references
  • Version 1.3: 2015-02-04
    Changes: Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Non-polymer description, Structure summary