9RFF | pdb_00009rff

Crystal Structure of Human Rac1 Fused with the Scaffold Protein POSH (residues 319-371)

• PDB DOI: https://doi.org/10.2210/pdb9RFF/pdb

• Classification: HYDROLASE
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2025-06-04 Released: 2025-12-03 
• Deposition Author(s): Kjaer, L.F., Ielasi, F.S., Palencia, A., Jensen, M.R.
• Funding Organization(s): Agence Nationale de la Recherche (ANR), European Union (EU)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.25 Å
• R-Value Free: 
  0.164 (Depositor), 0.164 (DCC) 
• R-Value Work: 
  0.134 (Depositor), 0.134 (DCC) 

Starting Model: experimental

Literature

Hierarchical Folding-Upon-Binding of an Intrinsically Disordered Protein

Kjaer, L.F., Ielasi, F.S., Winbolt, T., Delaforge, E., Tengo, M., Bessa, L.M., Marino-Perez, L., Boeri-Erba, E., Bouvignies, G., Palencia, A., Jensen, M.R.

(2025) Nat Commun 

• DOI: https://doi.org/10.1038/s41467-025-66420-5

Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: gel filtration

Macromolecule Content 

• Total Structure Weight: 26.23 kDa 
• Atom Count: 1,958 
• Modeled Residue Count: 221 
• Deposited Residue Count: 233 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Ras-related C3 botulinum toxin substrate 1,E3 ubiquitin-protein ligase SH3RF1	A	233	Homo sapiens	Mutation(s): 0  Gene Names: RAC1, TC25, MIG5, SH3RF1, KIAA1494, POSH, POSH1, RNF142, SH3MD2 EC: 3.6.5.2 (PDB Primary Data), 2.3.2.27 (PDB Primary Data)
UniProt & NIH Common Fund Data Resources
Find proteins for P63000 (Homo sapiens) Explore P63000  Go to UniProtKB:  P63000
PHAROS:  P63000 GTEx:  ENSG00000136238
Find proteins for Q7Z6J0 (Homo sapiens) Explore Q7Z6J0  Go to UniProtKB:  Q7Z6J0
PHAROS:  Q7Z6J0 GTEx:  ENSG00000154447
UniProt Groups	P63000Q7Z6J0

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
GNP (Subject of Investigation/LOI)	B [auth A]	PHOSPHOAMINOPHOSPHONIC ACID-GUANYLATE ESTER C10 H17 N6 O13 P3 UQABYHGXWYXDTK-UUOKFMHZSA-N
MPD	D [auth A]	(4S)-2-METHYL-2,4-PENTANEDIOL C6 H14 O2 SVTBMSDMJJWYQN-YFKPBYRVSA-N
MG	C [auth A]	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
CME	A	L-PEPTIDE LINKING	C5 H11 N O3 S2		CYS

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.25 Å
• R-Value Free:  0.164 (Depositor), 0.164 (DCC) 
• R-Value Work:  0.134 (Depositor), 0.134 (DCC) 

Diffraction Data: https://doi.org/10.15151/ESRF-ES-967510039

Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 39.222	α = 90
b = 73.082	β = 90
c = 73.283	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
autoPROC	data reduction
autoPROC	data scaling
PHASER	phasing

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2025-12-03 
Deposition Author(s): Kjaer, L.F., Ielasi, F.S., Palencia, A., Jensen, M.R.

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Funding Organization	Location	Grant Number
Agence Nationale de la Recherche (ANR)	France	ANR-21-CE11-0033
Agence Nationale de la Recherche (ANR)	France	ANR-10-INBS-0005-02
Agence Nationale de la Recherche (ANR)	France	ANR-17-EURE-0003
European Union (EU)	European Union	HORIZON-MSCA-2022-DN-01

Revision History  

• Version 1.0: 2025-12-03
  Type: Initial release