3W37

Sugar beet alpha-glucosidase with acarbose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.154 
  • R-Value Observed: 0.154 

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Ligand Structure Quality Assessment 


This is version 2.0 of the entry. See complete history


Literature

Molecular basis for the recognition of long-chain substrates by plant & alpha-glucosidase

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

(2013) J Biol Chem 288: 19296-19303

  • DOI: https://doi.org/10.1074/jbc.M113.465211
  • Primary Citation of Related Structures:  
    3W37, 3W38

  • PubMed Abstract: 

    Sugar beet α-glucosidase (SBG), a member of glycoside hydrolase family 31, shows exceptional long-chain specificity, exhibiting higher kcat/Km values for longer malto-oligosaccharides. However, its amino acid sequence is similar to those of other short chain-specific α-glucosidases. To gain structural insights into the long-chain substrate recognition of SBG, a crystal structure complex with the pseudotetrasaccharide acarbose was determined at 1.7 Å resolution. The active site pocket of SBG is formed by a (β/α)8 barrel domain and a long loop (N-loop) bulging from the N-terminal domain similar to other related enzymes. Two residues (Phe-236 and Asn-237) in the N-loop are important for the long-chain specificity. Kinetic analysis of an Asn-237 mutant enzyme and a previous study of a Phe-236 mutant enzyme demonstrated that these residues create subsites +2 and +3. The structure also indicates that Phe-236 and Asn-237 guide the reducing end of long substrates to subdomain b2, which is an additional element inserted into the (β/α)8 barrel domain. Subdomain b2 of SBG includes Ser-497, which was identified as the residue at subsite +4 by site-directed mutagenesis.


  • Organizational Affiliation

    Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Alpha-glucosidase913Beta vulgarisMutation(s): 0 
EC: 3.2.1.20
UniProt
Find proteins for L0N7E5 (Beta vulgaris)
Explore L0N7E5 
Go to UniProtKB:  L0N7E5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupL0N7E5
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
B
2N-Glycosylation
Glycosylation Resources
GlyTouCan:  G42666HT
GlyCosmos:  G42666HT
GlyGen:  G42666HT
Entity ID: 3
MoleculeChains 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
C
3N-Glycosylation
Glycosylation Resources
GlyTouCan:  G11971MR
GlyCosmos:  G11971MR
GlyGen:  G11971MR
Entity ID: 4
MoleculeChains 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
D
3N/AN/A
Glycosylation Resources
GlyTouCan:  G66431MI
GlyCosmos:  G66431MI
Small Molecules
Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download Ideal Coordinates CCD File 
J [auth A]2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
SO4
Query on SO4

Download Ideal Coordinates CCD File 
H [auth A]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
GOL
Query on GOL

Download Ideal Coordinates CCD File 
F [auth A],
I [auth A],
L [auth A]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
ACY
Query on ACY

Download Ideal Coordinates CCD File 
E [auth A],
G [auth A],
K [auth A]
ACETIC ACID
C2 H4 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-N
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.154 
  • R-Value Observed: 0.154 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 86.36α = 90
b = 98.2β = 90
c = 108.75γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
PHASERphasing
PHENIXrefinement
PDB_EXTRACTdata extraction
BSSdata collection
XDSdata reduction

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-05-29
    Type: Initial release
  • Version 1.1: 2013-06-12
    Changes: Database references
  • Version 1.2: 2013-07-17
    Changes: Database references
  • Version 1.3: 2014-07-30
    Changes: Other
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Non-polymer description, Structure summary