23SR | pdb_000023sr

Cryo-EM structure of CDK2 in complex with CRBN/DDB1 and B11


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.85 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation

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This is version 1.0 of the entry. See complete history

Literature

Selective CDK2 Degradation via Noncanonical Recruitment.

Pei, Y.Lin, W.Li, X.Meng, Y.Yin, Y.Pan, B.Zhou, L.Cao, L.Cang, Y.Jiang, Y.Lu, W.Meng, Z.

(2026) J Med Chem 

  • DOI: https://doi.org/10.1021/acs.jmedchem.6c01264
  • Primary Citation Related Structures: 
    23SR

  • PubMed Abstract: 

    Cyclin-dependent kinase 2 (CDK2) represents a critical therapeutic target in tumors resistant to CDK4/6 inhibitors or with CCNE1 amplification. However, selective inhibition of CDK2 remains challenging owing to the high structural homology among CDKs. In this study, we identify B10 and B12 as cereblon (CRBN)-based molecular glue degraders that selectively degrade CDK2. Ternary complex structures reveal a noncanonical recruitment mode centered on CDK2 Glu57, which bypasses the canonical G-loop/β-hairpin and kinase glycine-rich loop interactions and is stabilized by an extended CRBN-CDK2 interface. Mechanistically, these degraders inhibit retinoblastoma (Rb) phosphorylation and induce G1/S-phase arrest, suppressing CDK2-dependent cell proliferation. B12 further exhibits improved pharmacokinetics, measurable oral bioavailability, and in vivo target engagement, achieving intratumoral CDK2 degradation following intraperitoneal administration. Collectively, this study provides a structural blueprint for designing selective kinase degraders and establishes B12 as a chemically tractable probe for targeting CDK2-driven malignancies.


  • Organizational Affiliation
    • School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.

Macromolecule Content 

  • Total Structure Weight: 229.82 kDa 
  • Atom Count: 11,664 
  • Modeled Residue Count: 1,498 
  • Deposited Residue Count: 2,042 
  • Unique protein chains: 3

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Protein cereblonA [auth B]477Homo sapiensMutation(s): 0 
Gene Names: CRBNAD-006
UniProt & NIH Common Fund Data Resources
Find proteins for Q96SW2 (Homo sapiens)
Explore Q96SW2 
Go to UniProtKB:  Q96SW2
PHAROS:  Q96SW2
GTEx:  ENSG00000113851 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ96SW2
Sequence Annotations
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Reference Sequence
Find similar proteins by:|  3D Structure
Entity ID: 2
MoleculeChains  Sequence LengthOrganismDetailsImage
Oplophorus-luciferin 2-monooxygenase catalytic subunit,Cyclin-dependent kinase 2,GFP-like fluorescent chromoproteinB [auth C]729synthetic constructHomo sapiensMutation(s): 0 
EC: 2.7.11.22
UniProt & NIH Common Fund Data Resources
Find proteins for P24941 (Homo sapiens)
Explore P24941 
Go to UniProtKB:  P24941
PHAROS:  P24941
GTEx:  ENSG00000123374 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP24941
Sequence Annotations
Expand
Reference Sequence
Find similar proteins by:|  3D Structure
Entity ID: 3
MoleculeChains  Sequence LengthOrganismDetailsImage
DNA damage-binding protein 1C [auth A]836Homo sapiensMutation(s): 0 

Small Molecules

Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
A1E59(
Subject of Investigation/LOI)

Query on A1E59



Download:Ideal Coordinates CCD File
D [auth B]spiro[3.3]heptan-2-ylmethyl ~{N}-[[3-[(3~{R})-2,6-bis(oxidanylidene)piperidin-3-yl]-8-chloranyl-6-fluoranyl-4-oxidanylidene-quinazolin-7-yl]methyl]carbamate
C23 H24 Cl F N4 O5
BALILEYXPAKABK-MRXNPFEDSA-N

Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.85 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
MODEL REFINEMENTPHENIX1.20.1_4487
RECONSTRUCTIONCoot

Structure Validation

Currently 23SR does not have a validation slider image.



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Natural Science Foundation of China (NSFC)China--

Revision History  (Full details and data files)

  • Version 1.0: 2026-07-01
    Type: Initial release