6M8C

Crystal structure of the core catalytic domain of human inositol phosphate multikinase in complex with isorhamnetin

  • Classification: TRANSFERASE
  • Organism(s): Homo sapiens
  • Expression System: Escherichia coli
  • Mutation(s): No 

  • Deposited: 2018-08-21 Released: 2019-01-23 
  • Deposition Author(s): Wang, H., Shears, S.B.
  • Funding Organization(s): National Institutes of Health/National Institute of Environmental Health Sciences (NIH/NIEHS)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.171 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Inhibition of Inositol Polyphosphate Kinases by Quercetin and Related Flavonoids: A Structure-Activity Analysis.

Gu, C.Stashko, M.A.Puhl-Rubio, A.C.Chakraborty, M.Chakraborty, A.Frye, S.V.Pearce, K.H.Wang, X.Shears, S.B.Wang, H.

(2019) J Med Chem 62: 1443-1454

  • DOI: https://doi.org/10.1021/acs.jmedchem.8b01593
  • Primary Citation of Related Structures:  
    6M88, 6M89, 6M8A, 6M8B, 6M8C, 6M8D, 6M8E

  • PubMed Abstract: 

    Dietary flavonoids inhibit certain protein kinases and phospholipid kinases by competing for their ATP-binding sites. These nucleotide pockets have structural elements that are well-conserved in two human small-molecule kinases, inositol hexakisphosphate kinase (IP6K) and inositol polyphosphate multikinase (IPMK), which synthesize multifunctional inositol phosphate cell signals. Herein, we demonstrate that both kinases are inhibited by quercetin and 16 related flavonoids; IP6K is the preferred target. Relative inhibitory activities were rationalized by X-ray analysis of kinase/flavonoid crystal structures; this detailed structure-activity analysis revealed hydrophobic and polar ligand/protein interactions, the degree of flexibility of key amino acid side chains, and the importance of water molecules. The seven most potent IP6K inhibitors were incubated with intact HCT116 cells at concentrations of 2.5 μM; diosmetin was the most selective and effective IP6K inhibitor (>70% reduction in activity). Our data can instruct on pharmacophore properties to assist the future development of inositol phosphate kinase inhibitors. Finally, we propose that dietary flavonoids may inhibit IP6K activity in cells that line the gastrointestinal tract.


  • Organizational Affiliation

    Inositol Signaling Group, Signal Transduction Laboratory , National Institute of Environmental Health Sciences , Research Triangle Park , North Carolina 27709 , United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Inositol polyphosphate multikinase,Inositol polyphosphate multikinase261Homo sapiensMutation(s): 0 
Gene Names: IPMKIMPK
EC: 2.7.1.151
UniProt & NIH Common Fund Data Resources
Find proteins for Q8NFU5 (Homo sapiens)
Explore Q8NFU5 
Go to UniProtKB:  Q8NFU5
PHAROS:  Q8NFU5
GTEx:  ENSG00000151151 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8NFU5
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
IRH
Query on IRH

Download Ideal Coordinates CCD File 
B [auth A]isorhamnetin
C16 H12 O7
IZQSVPBOUDKVDZ-UHFFFAOYSA-N
Binding Affinity Annotations 
IDSourceBinding Affinity
IRH Binding MOAD:  6M8C IC50: 2200 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.171 
  • Space Group: P 42 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.23α = 90
b = 78.23β = 90
c = 85.12γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
REFMACphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of Environmental Health Sciences (NIH/NIEHS)United States1ZIAES080046-29

Revision History  (Full details and data files)

  • Version 1.0: 2019-01-23
    Type: Initial release
  • Version 1.1: 2019-05-01
    Changes: Data collection, Database references
  • Version 1.2: 2019-12-18
    Changes: Author supporting evidence
  • Version 1.3: 2023-10-11
    Changes: Data collection, Database references, Refinement description