2DDK

Crystal structure of human myo-inositol monophosphatase 2 (IMPA2) (orthorhombic form)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.260 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of human myo-inositol monophosphatase 2, the product of the putative susceptibility gene for bipolar disorder, schizophrenia, and febrile seizures

Arai, R.Ito, K.Ohnishi, T.Ohba, H.Akasaka, R.Bessho, Y.Hanawa-Suetsugu, K.Yoshikawa, T.Shirouzu, M.Yokoyama, S.

(2007) Proteins 67: 732-742

  • DOI: 10.1002/prot.21299
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The human IMPA2 gene, which encodes myo-inositol monophosphatase 2 (IMPA2), is mapped onto 18p11.2, a susceptibility region for bipolar disorder. This chromosomal region has also been proposed to include a susceptibility locus for schizophrenia and f ...

    The human IMPA2 gene, which encodes myo-inositol monophosphatase 2 (IMPA2), is mapped onto 18p11.2, a susceptibility region for bipolar disorder. This chromosomal region has also been proposed to include a susceptibility locus for schizophrenia and febrile seizures. Here we report the crystal structures of human IMPA2 and its complex with calcium and phosphate ions. Human IMPA2 comprises an alpha-beta protein with a five-layered sandwich of alpha-helices and beta-sheets (alpha-beta-alpha-beta-alpha). The crystal structure and analytical ultracentrifugation results indicated that IMPA2 exists as a dimer in solution. The overall structure of IMPA2 is similar to that of IMPA1, except for the loop regions. In IMPA1, the loop region (31-43) is located at the entrance of the active site cavity. In the corresponding region (42-54) of IMPA2, the residues are disordered and partially form an alpha-helix. The structural difference in the opening of the active site cavity suggests that the substrate specificity differs between IMPA1 and IMPA2. The widely opened cavity of IMPA2 implies that the physiological substrate may be a larger compound than inositol monophosphate. The structure of IMPA2 complexed with Ca2+ revealed two metals and one phosphate binding sites, which were the same sites as in IMPA1 complexed with Mn2+ and phosphate, suggesting that the mechanism of the enzymatic reaction is similar to that of IMPA1. The crystal structures of human IMPA2 are useful for understanding the effect of nonsynonymous polymorphism reported in IMPA2, and will contribute to further functional analyses of IMPA2 that potentially predisposes to the vulnerabilities of bipolar disorder, schizophrenia, and febrile seizures.


    Organizational Affiliation

    Protein Research Group, RIKEN Genomic Sciences Center, Tsurumi, Yokohama 230-0045, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Inositol monophosphatase 2
A, B
299Homo sapiensMutation(s): 0 
Gene Names: IMPA2 (IMP.18P)
EC: 3.1.3.25
Find proteins for O14732 (Homo sapiens)
Go to Gene View: IMPA2
Go to UniProtKB:  O14732
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.260 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 65.457α = 90.00
b = 95.639β = 90.00
c = 107.239γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
HKL-2000data reduction
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-02-06
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance