Human MST3 (STK24) kinase in complex with inhibitor MRLW5

Experimental Data Snapshot

  • Resolution: 2.52 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.185 

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Ligand Structure Quality Assessment 

This is version 2.1 of the entry. See complete history


Development of Selective Pyrido[2,3- d ]pyrimidin-7(8 H )-one-Based Mammalian STE20-Like (MST3/4) Kinase Inhibitors.

Rak, M.Menge, A.Tesch, R.Berger, L.M.Balourdas, D.I.Shevchenko, E.Kramer, A.Elson, L.Berger, B.T.Abdi, I.Wahl, L.M.Poso, A.Kaiser, A.Hanke, T.Kronenberger, T.Joerger, A.C.Muller, S.Knapp, S.

(2024) J Med Chem 67: 3813-3842

  • DOI: https://doi.org/10.1021/acs.jmedchem.3c02217
  • Primary Citation of Related Structures:  
    8BZJ, 8QLR, 8QLS, 8QLT

  • PubMed Abstract: 

    Mammalian STE20-like (MST) kinases 1-4 play key roles in regulating the Hippo and autophagy pathways, and their dysregulation has been implicated in cancer development. In contrast to the well-studied MST1/2, the roles of MST3/4 are less clear, in part due to the lack of potent and selective inhibitors. Here, we re-evaluated literature compounds, and used structure-guided design to optimize the p21-activated kinase (PAK) inhibitor G-5555 ( 8 ) to selectively target MST3/4. These efforts resulted in the development of MR24 ( 24 ) and MR30 ( 27 ) with good kinome-wide selectivity and high cellular potency. The distinct cellular functions of closely related MST kinases can now be elucidated with subfamily-selective chemical tool compounds using a combination of the MST1/2 inhibitor PF-06447475 ( 2 ) and the two MST3/4 inhibitors developed. We found that MST3/4-selective inhibition caused a cell-cycle arrest in the G1 phase, whereas MST1/2 inhibition resulted in accumulation of cells in the G2/M phase.

  • Organizational Affiliation

    Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Serine/threonine-protein kinase 24
A, B
306Homo sapiensMutation(s): 0 
Gene Names: STK24MST3STK3
UniProt & NIH Common Fund Data Resources
Find proteins for Q9Y6E0 (Homo sapiens)
Explore Q9Y6E0 
Go to UniProtKB:  Q9Y6E0
GTEx:  ENSG00000102572 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9Y6E0
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
SJX (Subject of Investigation/LOI)
Query on SJX

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
C24 H25 Cl N6 O
Query on EDO

Download Ideal Coordinates CCD File 
E [auth B]1,2-ETHANEDIOL
C2 H6 O2
Experimental Data & Validation

Experimental Data

  • Resolution: 2.52 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.185 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.049α = 88.855
b = 57.737β = 89.175
c = 61.771γ = 62.12
Software Package:
Software NamePurpose
XDSdata reduction
Aimlessdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
German Research Foundation (DFG)GermanyJO 1473/1-3

Revision History  (Full details and data files)

  • Version 1.0: 2023-01-18
    Type: Initial release
  • Version 2.0: 2023-05-24
    Changes: Non-polymer description
  • Version 2.1: 2024-06-19
    Changes: Data collection, Database references