5TA6

Crystal structure of PLK1 in complex with a novel 5,6-dihydroimidazolo[1,5-f]pteridine inhibitor.

• PDB DOI: https://doi.org/10.2210/pdb5TA6/pdb

• Classification: Transferase/Transferase Inhibitor
• Organism(s): Homo sapiens
• Expression System: unidentified baculovirus
• Mutation(s): No 


• Deposited: 2016-09-09 Released: 2017-02-22 
• Deposition Author(s): Skene, R.J., Hosfield, D.J.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.260 
• R-Value Work: 0.179 
• R-Value Observed: 0.183 

Literature

Structure-based design and SAR development of 5,6-dihydroimidazolo[1,5-f]pteridine derivatives as novel Polo-like kinase-1 inhibitors.

Kiryanov, A., Natala, S., Jones, B., McBride, C., Feher, V., Lam, B., Liu, Y., Honda, K., Uchiyama, N., Kawamoto, T., Hikichi, Y., Zhang, L., Hosfield, D., Skene, R., Zou, H., Stafford, J., Cao, X., Ichikawa, T.

(2017) Bioorg Med Chem Lett 27: 1311-1315

• PubMed: 28169164 
• DOI: https://doi.org/10.1016/j.bmcl.2016.10.009
• Primary Citation of Related Structures:  
  5TA6, 5TA8


• PubMed Abstract: 
  

  Using structure-based drug design, we identified a novel series of 5,6-dihydroimidazolo[1,5-f]pteridine PLK1 inhibitors. Rational improvements to compounds of this class resulted in single-digit nanomolar enzyme and cellular activity against PLK1, and oral bioavailability. Compound 1 exhibits >7 fold induction of phosphorylated Histone H3 and is efficacious in an in vivo HT-29 tumor xenograft model.

---

Organizational Affiliation: 

Takeda California, 10410 Science Center Drive, San Diego 92121, USA. Electronic address: [e-mail].

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 41.2 kDa 
• Atom Count: 2,534 
• Modelled Residue Count: 294 
• Deposited Residue Count: 358 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Serine/threonine-protein kinase PLK1	A	358	Homo sapiens	Mutation(s): 0  Gene Names: PLK1, PLK EC: 2.7.11.21
UniProt & NIH Common Fund Data Resources
Find proteins for P53350 (Homo sapiens) Explore P53350  Go to UniProtKB:  P53350
PHAROS:  P53350 GTEx:  ENSG00000166851

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
79D	B [auth A]	4-{[(6R)-7-cyano-5-cyclopentyl-6-ethyl-5,6-dihydroimidazo[1,5-f]pteridin-3-yl]amino}-3-methoxy-N-(1-methylpiperidin-4-yl)benzamide C30 H37 N9 O2 UJEXFMKGBVBXPF-XMMPIXPASA-N
ZN	C [auth A]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
79D	Binding MOAD:  5TA6	IC50: 1.5 (nM) from 1 assay(s)
	BindingDB:  5TA6	IC50: 1.5 (nM) from 1 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.260 
• R-Value Work: 0.179 
• R-Value Observed: 0.183 
• Space Group: P 3₂ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 66.303	α = 90
b = 66.303	β = 90
c = 153.115	γ = 120

Software Package:

Software Name	Purpose
SCALEPACK	data scaling
REFMAC	refinement
PDB_EXTRACT	data extraction
MOLREP	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2017-02-22 
Deposition Author(s): Skene, R.J., Hosfield, D.J.

Revision History  

• Version 1.0: 2017-02-22
  Type: Initial release
  
• Version 1.1: 2017-03-08
  Changes: Database references
• Version 1.2: 2024-03-06
  Changes: Data collection, Database references, Derived calculations