1W2F

Human Inositol (1,4,5)-trisphosphate 3-kinase substituted with selenomethionine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.203 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure of a Human Inositol 1,4,5-Trisphosphate 3-Kinase; Substrate Binding Reveals Why It is not a Phosphoinositide 3-Kinase

Gonzalez, B.Schell, M.J.Letcher, A.J.Veprintsev, D.B.Irvine, R.F.Williams, R.L.

(2004) Mol.Cell 15: 689

  • DOI: 10.1016/j.molcel.2004.08.004
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Mammalian cells produce a variety of inositol phosphates (InsPs), including Ins(1,4,5)P3 that serves both as a second messenger and as a substrate for inositol polyphosphate kinases (IPKs), which further phosphorylate it. We report the structure of a ...

    Mammalian cells produce a variety of inositol phosphates (InsPs), including Ins(1,4,5)P3 that serves both as a second messenger and as a substrate for inositol polyphosphate kinases (IPKs), which further phosphorylate it. We report the structure of an IPK, the human Ins(1,4,5)P3 3-kinase-A, both free and in complexes with substrates and products. This enzyme catalyzes transfer of a phosphate from ATP to the 3-OH of Ins(1,4,5)P3, and its X-ray crystal structure provides a template for understanding a broad family of InsP kinases. The catalytic domain consists of three lobes. The N and C lobes bind ATP and resemble protein and lipid kinases, despite insignificant sequence similarity. The third lobe binds inositol phosphate and is a unique four-helix insertion in the C lobe. This lobe embraces all of the phosphates of Ins(1,4,5)P3 in a positively charged pocket, explaining the enzyme's substrate specificity and its inability to phosphorylate PtdIns(4,5)P2, the membrane-resident analog of Ins(1,4,5)P3.


    Organizational Affiliation

    MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
INOSITOL-TRISPHOSPHATE 3-KINASE A
A, B
276Homo sapiensMutation(s): 0 
Gene Names: ITPKA
EC: 2.7.1.127
Find proteins for P23677 (Homo sapiens)
Go to Gene View: ITPKA
Go to UniProtKB:  P23677
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.203 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 69.304α = 90.00
b = 95.798β = 90.00
c = 180.352γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
MOSFLMdata reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-09-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance