8C12 image
Entry Detail
PDB ID:
8C12
Keywords:
Title:
Identification of an intermediate activation state of PAK5 reveals a novel mechanism of kinase inhibition.
Biological Source:
PDB Version:
Deposition Date:
2022-12-19
Release Date:
2023-10-25
Method Details:
Experimental Method:
Resolution:
1.55 Å
R-Value Free:
0.23
R-Value Work:
0.19
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Serine/threonine-protein kinase PAK 5
Chain IDs:A (auth: AAA)
Chain Length:295
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:PAK5-Af17
Chain IDs:B (auth: BBB)
Chain Length:106
Number of Molecules:1
Biological Source:synthetic construct
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
SEP A SER modified residue
Primary Citation
Affimer-mediated locking of p21-activated kinase 5 in an intermediate activation state results in kinase inhibition.
Cell Rep 42 113184 113184 (2023)
PMID: 37776520 DOI: 10.1016/j.celrep.2023.113184

Abstact

Kinases are important therapeutic targets, and their inhibitors are classified according to their mechanism of action, which range from blocking ATP binding to covalent inhibition. Here, a mechanism of inhibition is highlighted by capturing p21-activated kinase 5 (PAK5) in an intermediate state of activation using an Affimer reagent that binds in the P+1 pocket. PAK5 was identified from a non-hypothesis-driven high-content imaging RNAi screen in urothelial cancer cells. Silencing of PAK5 resulted in reduced cell number, G1/S arrest, and enlargement of cells, suggesting it to be important in urothelial cancer cell line survival and proliferation. Affimer reagents were isolated to identify mechanisms of inhibition. The Affimer PAK5-Af17 recapitulated the phenotype seen with siRNA. Co-crystallization revealed that PAK5-Af17 bound in the P+1 pocket of PAK5, locking the kinase into a partial activation state. This mechanism of inhibition indicates that another class of kinase inhibitors is possible.

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Primary Citation of related structures