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: 2.2 Å
  • R-Value Work: 0.153 

wwPDB Validation 3D Report Full Report


This is version 1.3 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

  • Also Cited By: 1HX0

  • 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 ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ALPHA-AMYLASE
A
496Sus scrofaGene Names: AMY2
EC: 3.2.1.1
Find proteins for P00690 (Sus scrofa)
Go to UniProtKB:  P00690
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

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Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
CA
Query on CA

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

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A
BETA-D-GLUCOSE
C6 H12 O6
WQZGKKKJIJFFOK-VFUOTHLCSA-N
 Ligand Interaction
GLC
Query on GLC

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Download CCD File 
A
ALPHA-D-GLUCOSE
C6 H12 O6
WQZGKKKJIJFFOK-DVKNGEFBSA-N
 Ligand Interaction
DAF
Query on DAF

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A
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
C13 H17 N O8
ZGWNRGISVMYHTF-KKXLKBQTSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Work: 0.153 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 56.300α = 90.00
b = 87.800β = 90.00
c = 103.400γ = 90.00
Software Package:
Software NamePurpose
X-PLORphasing
X-PLORrefinement
X-PLORmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1995-05-24
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-11-29
    Type: Derived calculations, Other