1IMF

STRUCTURAL STUDIES OF METAL BINDING BY INOSITOL MONOPHOSPHATASE: EVIDENCE FOR TWO-METAL ION CATALYSIS

  • Classification: HYDROLASE
  • Organism(s): Homo sapiens
  • Mutation(s): No 

  • Deposited: 1994-02-08 Released: 1995-02-27 
  • Deposition Author(s): Bone, R.

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Work: 0.177 
  • R-Value Observed: 0.177 

wwPDB Validation   3D Report Full Report


This is version 1.5 of the entry. See complete history


Literature

Structural studies of metal binding by inositol monophosphatase: evidence for two-metal ion catalysis.

Bone, R.Frank, L.Springer, J.P.Atack, J.R.

(1994) Biochemistry 33: 9468-9476

  • DOI: 10.1021/bi00198a012
  • Primary Citation of Related Structures:  
    1IMF, 1IME, 1IMD, 1IMC

  • PubMed Abstract: 
  • The structure of inositol monophosphatase has been determined to 2.60 A resolution in complexes with Mn2+ and with Mn2+ and phosphate. In the Mn2+ complex, three metal cations and one Cl were bound in the active site on each of the two subunits of the enzyme ...

    The structure of inositol monophosphatase has been determined to 2.60 A resolution in complexes with Mn2+ and with Mn2+ and phosphate. In the Mn2+ complex, three metal cations and one Cl were bound in the active site on each of the two subunits of the enzyme. Ligands to the three metals include the side chains of Glu 70, Asp 90, Asp 93, and Asp 220, t he carbonyl group of Ile 92, several solvent molecules and the chloride, which is a ligand to each of the cations. When phosphate is soaked into these Mn2+ cocrystals, one of the three Mn2+ ions is expelled from the active site, leaving metal ions with octahedral and tetrahedral coordination geometry. In addition, the structure of apoinositol monophosphatase was determined to 2.5 A resolution. Residues 70-75, a two-turn helical segment which is involved in metal coordination, moves away from the metal binding site by 2-3 A in the absence of cations. Residues 30-40, which wrap around the metal binding site and interact with the metal indirectly through solvent molecules and protein ligands to the metal, become disordered in the absence of metal. In various metal complexes, segmental mobility is also observed in the residues which form the metal binding sites. The results of these studies of the interaction of inositol monophosphatase with cations suggest that the enzyme accomplishes phosphate ester hydrolysis using two metal ions, one with octahedral and one with tetrahedral coordination geometry. Broad metal-binding specificity appears to result from extensive flexibility in several of the protein segments which contribute metal ligands, from the presence of alternate metal ligands and from metal coordination spheres which include water molecules.


    Related Citations: 
    • Cdna Cloning of Human and Rat Brain Myo-Inositol Monophosphatase. Expression and Characterization of the Human Recombinant Enzyme
      Mcallister, G., Whiting, P., Hammond, E.A., Knowles, M.R., Atack, J.R., Bailey, F.J., Maigetter, R., Ragan, C.I.
      (1992) Biochem J 284: 749
    • Structure of Inositol Monophosphatase, the Putative Target of Lithium Therapy
      Bone, R., Springer, J.P., Atack, J.R.
      (1992) Proc Natl Acad Sci U S A 89: 10031

    Organizational Affiliation

    Department of Biophysical Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
INOSITOL MONOPHOSPHATASEA277Homo sapiensMutation(s): 0 
Gene Names: CDNAIMPA1IMPA
EC: 3.1.3.25 (PDB Primary Data), 3.1.3.94 (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for P29218 (Homo sapiens)
Explore P29218 
Go to UniProtKB:  P29218
PHAROS:  P29218
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Work: 0.177 
  • R-Value Observed: 0.177 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 100.83α = 90
b = 100.83β = 90
c = 62.51γ = 120
Software Package:
Software NamePurpose
X-PLORmodel building
PROLSQrefinement
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 1994-02-08 
  • Released Date: 1995-02-27 
  • Deposition Author(s): Bone, R.

Revision History  (Full details and data files)

  • Version 1.0: 1995-02-27
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Advisory, Derived calculations, Other
  • Version 1.4: 2019-07-17
    Changes: Data collection, Refinement description
  • Version 1.5: 2019-08-14
    Changes: Data collection, Refinement description