9MMS

Cryo-EM structure of CRAF/MEK1 complex (kinase domain, CRAF Y340D/Y341D mutant)

Summary for 9MMS

• Entry DOI: 10.2210/pdb9mms/pdb
• EMDB information: 48402
• Descriptor: RAF proto-oncogene serine/threonine-protein kinase, Dual specificity mitogen-activated protein kinase kinase 1, PHOSPHOTHIOPHOSPHORIC ACID-ADENYLATE ESTER, ... (5 entities in total)
• Functional Keywords: craf-mek1-14-3-3 complex, mapk pathway, transferase
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 2
• Total formula weight: 124367.47

Authors

Jang, D.M.,Jeon, H.,Eck, M.J. (deposition date: 2024-12-20, release date: 2025-09-10, Last modification date: 2025-10-08)

Primary citation

Jang, D.M.,Boxer, K.,Ha, B.H.,Tkacik, E.,Levitz, T.,Rawson, S.,Metivier, R.J.,Schmoker, A.,Jeon, H.,Eck, M.J.
Cryo-EM structures of CRAF/MEK1/14-3-3 complexes in autoinhibited and open-monomer states reveal features of RAF regulation.
Nat Commun, 16:8150-8150, 2025

PubMed Abstract: CRAF (RAF1) is one of three RAF-family kinases that initiate MAP kinase signaling in response to activated RAS and is essential for oncogenic signaling from mutant KRAS. Like BRAF, CRAF is regulated by 14-3-3 engagement and by intramolecular autoinhibitory interactions of its N-terminal regulatory region. Unlike BRAF, it is thought to require tyrosine phosphorylation in its N-terminal acidic (NtA) motif for full catalytic activation. Here we describe cryo-EM reconstructions of full-length CRAF in complex with MEK1 and a 14-3-3 dimer. These structures reveal a fully autoinhibited conformation analogous to that observed for BRAF and two "open monomer" states in which the inhibitory interactions of the CRD and 14-3-3 dimer are released or rearranged, but the kinase domain remains inactive. Structure-function studies of the NtA motif indicate that phosphorylation or acidic mutations in this segment increase catalytic activity by destabilizing the inactive conformation of the kinase domain. Collectively, these studies provide a structural foundation for understanding the shared and unique regulatory features of CRAF and will inform efforts to selectively block CRAF signaling in cancer.

PubMed: 40890113
DOI: 10.1038/s41467-025-63227-2

Experimental method

ELECTRON MICROSCOPY (3.3 Å)