1PPI

THE ACTIVE CENTER OF A MAMMALIAN ALPHA-AMYLASE. THE STRUCTURE OF THE COMPLEX OF A PANCREATIC ALPHA-AMYLASE WITH A CARBOHYDRATE INHIBITOR REFINED TO 2.2 ANGSTROMS RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Work: 0.153 
  • R-Value Observed: 0.153 

wwPDB Validation   3D Report Full Report


This is version 2.0 of the entry. See complete history


Literature

The active center of a mammalian alpha-amylase. Structure of the complex of a pancreatic alpha-amylase with a carbohydrate inhibitor refined to 2.2-A resolution.

Qian, M.Haser, R.Buisson, G.Duee, E.Payan, F.

(1994) Biochemistry 33: 6284-6294

  • DOI: 10.1021/bi00186a031
  • Primary Citation of Related Structures:  
    1PPI

  • PubMed Abstract: 
  • An X-ray structure analysis of a crystal of pig pancreatic alpha-amylase (EC 3.2.1.1) that was soaked with acarbose (a pseudotetrasaccharide alpha-amylase inhibitor) showed electron density corresponding to five fully occupied subsites in the active site ...

    An X-ray structure analysis of a crystal of pig pancreatic alpha-amylase (EC 3.2.1.1) that was soaked with acarbose (a pseudotetrasaccharide alpha-amylase inhibitor) showed electron density corresponding to five fully occupied subsites in the active site. The crystal structure was refined to an R-factor of 15.3%, with a root mean square deviation in bond distances of 0.015 A. The model includes all 496 residues of the enzyme, one calcium ion, one chloride ion, 393 water molecules, and five bound sugar rings. The pseudodisaccharide acarviosine that is the essential structural unit responsible for the activity of all inhibitors of the acarbose type was located at the catalytic center. The carboxylic oxygens of the catalytically competent residues Glu233 and Asp300 form hydrogen bonds with the "glycosidic" NH group of the acarviosine group. The third residue of the catalytic triad Asp197 is located on the opposite side of the inhibitor binding cleft with one of its carbonyl oxygens at a 3.3-A distance from the anomeric carbon C-1 of the inhibitor center. Binding of inhibitor induces structural changes at the active site of the enzyme. A loop region between residues 304 and 309 moves in toward the bound saccharide, the resulting maximal mainchain movement being 5 A for His305. The side chain of residue Asp300 rotates upon inhibitor binding and makes strong van der Waals contacts with the imidazole ring of His299. Four histidine residues (His101, His201, His299, and His305) are found to be hydrogen-bonded with the inhibitor. Many protein-inhibitor hydrogen bond interactions are observed in the complex structure, as is clear hydrophobic stacking of aromatic residues with the inhibitor surface. The chloride activator ion and structural calcium ion are hydrogen-bonded via their ligands and water molecules to the catalytic residues.


    Related Citations: 
    • Structure and Molecular Model Refinement of Pig Pancreatic Alpha-Amylase at 2.1 Angstroms Resolution
      Qian, M., Haser, R., Payan, F.
      (1993) J Mol Biol 231: 785

    Organizational Affiliation

    LCCMB-CNRS, URA 1296, Faculté de Médecine Nord Bd Pierre Dramard, Marseille, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ALPHA-AMYLASEA496Sus scrofaMutation(s): 0 
Gene Names: AMY2
EC: 3.2.1.1
UniProt
Find proteins for P00690 (Sus scrofa)
Explore P00690 
Go to UniProtKB:  P00690
Protein Feature View
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  • Reference Sequence
Oligosaccharides

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Entity ID: 2
MoleculeChainsChain Length2D DiagramGlycosylation3D Interactions
alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranoseB2N/A Oligosaccharides Interaction
Glycosylation Resources
GlyTouCan:  G07411ON
GlyCosmos:  G07411ON
Entity ID: 3
MoleculeChainsChain Length2D DiagramGlycosylation3D Interactions
4,6-dideoxy-4-{[(1S,5R,6S)-3-formyl-5,6-dihydroxy-4-oxocyclohex-2-en-1-yl]amino}-alpha-D-xylo-hex-5-enopyranose-(1-4)-beta-D-glucopyranoseC2N/AN/A Oligosaccharides Interaction
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download Ideal Coordinates CCD File 
E [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download Ideal Coordinates CCD File 
D [auth A]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Biologically Interesting Molecules (External Reference) 1 Unique
Entity ID: 2
IDChainsNameType/Class2D Diagram3D Interactions
PRD_900001
Query on PRD_900001
Balpha-maltoseOligosaccharide / Nutrient Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Work: 0.153 
  • R-Value Observed: 0.153 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 56.3α = 90
b = 87.8β = 90
c = 103.4γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1995-05-24
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Database references, Derived calculations, Structure summary