9TYG | pdb_00009tyg

Structure of the MAP2K MEK1 in an inactive conformation in complex with its substrate MAPK ERK2

• PDB DOI: https://doi.org/10.2210/pdb9TYG/pdb
• EM Map EMD-56418: EMDB EMDataResource

• Classification: SIGNALING PROTEIN
• Organism(s): Homo sapiens, Toxoplasma gondii ME49
• Expression System: Trichoplusia ni, Escherichia coli
• Mutation(s): Yes 


• Deposited: 2026-01-19 Released: 2026-02-11 
• Deposition Author(s): von Velsen, J., Juyoux, P., Bowler, M.W.
• Funding Organization(s): Not funded

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 2.90 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Starting Model: in silico

Literature

Molecular basis of mitogen-activated protein kinase ERK2 activation by its upstream kinase MEK1

von Velsen, J., Juyoux, P., Piasentin, N., Fisher, H., Lapouge, K., Vadas, O., Gervasio, F.L., Bowler, M.W.

(2026) bioRxiv 

• DOI: https://doi.org/10.64898/2026.01.19.700303

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

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

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 87.59 kDa 
• Atom Count: 5,235 
• Modeled Residue Count: 645 
• Deposited Residue Count: 768 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Dual specificity mitogen-activated protein kinase kinase 1,Uncharacterized protein,Dual specificity mitogen-activated protein kinase kinase 1	A	405	Homo sapiens, Toxoplasma gondii ME49	Mutation(s): 2  Gene Names: MAP2K1, MEK1, PRKMK1, TGME49_230180 EC: 2.7.12.2
UniProt & NIH Common Fund Data Resources
Find proteins for Q02750 (Homo sapiens) Explore Q02750  Go to UniProtKB:  Q02750
PHAROS:  Q02750 GTEx:  ENSG00000169032
Find proteins for A0A125YG37 (Toxoplasma gondii (strain ATCC 50611 / Me49)) Explore A0A125YG37  Go to UniProtKB:  A0A125YG37
UniProt Groups	Q02750A0A125YG37

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Mitogen-activated protein kinase 1	B	363	Homo sapiens	Mutation(s): 1  Gene Names: MAPK1, ERK2, PRKM1, PRKM2 EC: 2.7.11.24
UniProt & NIH Common Fund Data Resources
Find proteins for P28482 (Homo sapiens) Explore P28482  Go to UniProtKB:  P28482
PHAROS:  P28482 GTEx:  ENSG00000100030

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ADP (Subject of Investigation/LOI)	C [auth A], E [auth B]	ADENOSINE-5'-DIPHOSPHATE C10 H15 N5 O10 P2 XTWYTFMLZFPYCI-KQYNXXCUSA-N
MG (Subject of Investigation/LOI)	D [auth A]	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 2.90 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX	1.21.2_5419+SVN
RECONSTRUCTION	cryoSPARC	v4.7.0

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2026-02-11 
Deposition Author(s): von Velsen, J., Juyoux, P., Bowler, M.W.

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Funding Organization	Location	Grant Number
Not funded		--

Revision History  

• Version 1.0: 2026-02-11
  Type: Initial release