Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

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

Biological Assembly Evidence: authors reported there is no experimental evidence

Macromolecule Content

• Total Structure Weight: 51351.98 
• Atom Count: 3072 
• Residue Count: 464 
• Unique protein chains: 1

5VYK

Crystal structure of the BRS domain of BRAF in complex with the CC-SAM domain of KSR1

• DOI: 10.2210/pdb5VYK/pdb

• Classification: SIGNALING PROTEIN
• Organism(s): Homo sapiens
• Expression System: Escherichia coli


• Deposited: 2017-05-25 Released: 2018-02-14 
• Deposition Author(s): Maisonneuve, P., Kurinov, I., Marullo, S.A., Lavoie, H., Thevakumaran, N., Sahmi, M., Jin, T., Therrien, M., SIcheri, F.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.749 Å
• R-Value Free: 0.239 
• R-Value Work: 0.217 

Literature

MEK drives BRAF activation through allosteric control of KSR proteins.

Lavoie, H., Sahmi, M., Maisonneuve, P., Marullo, S.A., Thevakumaran, N., Jin, T., Kurinov, I., Sicheri, F., Therrien, M.

(2018) Nature 554: 549-553

• PubMed: 29433126 
• DOI: 10.1038/nature25478
• Primary Citation of Related Structures:  
  5VR3


• PubMed Abstract: 
  

RAF family kinases have prominent roles in cancer. Their activation is dependent on dimerization of their kinase domains, which has emerged as a hindrance for drug development. In mammals, RAF family kinases include three catalytically competent enzymes (ARAF, BRAF and CRAF) and two pseudokinases (KSR1 and KSR2) that have been described as scaffolds owing to their apparent ability to bridge RAF isoforms and their substrate, mitogen-activated protein kinase kinase (MEK). Kinase suppressor of Ras (KSR) pseudokinases were also shown to dimerize with kinase-competent RAFs to stimulate catalysis allosterically. Although GTP-bound RAS can modulate the dimerization of RAF isoforms by engaging their RAS-binding domains, KSR1 and KSR2 lack an RAS-binding domain and therefore the regulatory principles underlying their dimerization with other RAF family members remain unknown. Here we show that the selective heterodimerization of BRAF with KSR1 is specified by direct contacts between the amino-terminal regulatory regions of each protein, comprising in part a novel domain called BRS in BRAF and the coiled-coil-sterile α motif (CC-SAM) domain in KSR1. We also discovered that MEK binding to the kinase domain of KSR1 asymmetrically drives BRAF-KSR1 heterodimerization, resulting in the concomitant stimulation of BRAF catalytic activity towards free MEK molecules. These findings demonstrate that KSR-MEK complexes allosterically activate BRAF through the action of N-terminal regulatory region and kinase domain contacts and challenge the accepted role of KSR as a scaffold for MEK recruitment to RAF.

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Organizational Affiliation: 

Institute for Research in Immunology and Cancer Laboratory of Intracellular Signaling Université de Montréal C.P. 6128, Succursale Centre-Ville Montréal, Québec H3C 3J7, Canada.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Chimera protein of BRS domain of BRAF and CC-SAM domain of KSR1,Serine/threonine-protein kinase B-raf	A, C	232	Homo sapiens	Mutation(s): 0  Gene Names: BRAF (BRAF1, RAFB1), KSR1 (KSR) EC: 2.7.11.1 2.7.11.1
Find proteins for P15056 (Homo sapiens) Go to Gene View: BRAF Go to UniProtKB:  P15056
Find proteins for Q8IVT5 (Homo sapiens) Go to Gene View: KSR1 Go to UniProtKB:  Q8IVT5

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
GOL	A, C	GLYCEROL GLYCERIN; PROPANE-1,2,3-TRIOL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.749 Å
• R-Value Free: 0.239 
• R-Value Work: 0.217 
• Space Group: C 1 2 1

Unit Cell:

Length (Å)	Angle (°)
a = 179.796	α = 90.00
b = 54.336	β = 106.68
c = 51.864	γ = 90.00

Software Package:

Software Name	Purpose
PDB_EXTRACT	data extraction
XDS	data reduction
PHENIX	refinement
PHASER	phasing
SCALA	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2017-05-25 
• Released Date: 2018-02-14 
• Deposition Author(s): Maisonneuve, P., Kurinov, I., Marullo, S.A., Lavoie, H., Thevakumaran, N., Sahmi, M., Jin, T., Therrien, M., SIcheri, F.

Revision History 

• Version 1.0: 2018-02-14
  Type: Initial release
• Version 1.1: 2018-02-28
  Type: Database references
• Version 1.2: 2018-03-07
  Type: Database references