Macromolecule Content

• Total Structure Weight: 31.03 kDa 
• Atom Count: 2169 
• Residue Count: 273 
• Unique protein chains: 2

2RMK

Rac1/PRK1 Complex

• DOI: 10.2210/pdb2RMK/pdb
• BMRB: 11010

• Classification: MEMBRANE PROTEIN/TRANSFERASE
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2007-10-25 Released: 2007-11-13 
• Deposition Author(s): Modha, R., Campbell, L.J., Nietlispach, D., Buhecha, H.R., Owen, D., Mott, H.R.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 25 
• Selection Criteria: structures with the lowest energy 

Literature

The Rac1 Polybasic Region Is Required for Interaction with Its Effector PRK1

Modha, R., Campbell, L.J., Nietlispach, D., Buhecha, H.R., Owen, D., Mott, H.R.

(2008) J Biol Chem 283: 1492-1500

• PubMed: 18006505 
• DOI: 10.1074/jbc.M706760200
• Primary Citation of Related Structures:  
  2RMK


• PubMed Abstract: 
  

Protein kinase C-related kinase 1 (PRK1 or PKN) is involved in regulation of the intermediate filaments of the actin cytoskeleton, as well as having effects on processes as diverse as mitotic timing and apoptosis. It is activated by interacting with the Rho family small G proteins and arachidonic acid or by caspase cleavage. We have previously shown that the HR1b of PRK1 binds exclusively to Rac1, whereas the HR1a domain binds to both Rac1 and RhoA. Here, we have determined the solution structure of the HR1b-Rac complex. We show that HR1b binds to the C-terminal end of the effector loop and switch 2 of Rac1. Comparison with the HR1a-RhoA structure shows that this part of the Rac1-HR1b interaction is homologous to one of the contact sites that HR1a makes with RhoA. The Rac1 used in this study included the C-terminal polybasic region, which is frequently omitted from structural studies, as well as the core G domain. The Rac1 C-terminal region reverses in direction to interact with residues in switch 2, and the polybasic region itself interacts with residues in HR1b. The interactions with HR1b do not prevent the polybasic region being available to contact the negatively charged membrane phospholipids, which is considered to be its primary role. This is the first structural demonstration that the C terminus of a G protein forms a novel recognition element for effector binding.

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Organizational Affiliation: 

Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, United Kingdom.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Ras-related C3 botulinum toxin substrate 1	A	192	Homo sapiens	Mutation(s): 1  Gene Names: RAC1, TC25, MIG5 EC: 3.6.5.2
Find proteins for P63000 (Homo sapiens) Explore P63000  Go to UniProtKB:  P63000
NIH Common Fund Data Resources
PHAROS  P63000 GTEx  ENSG00000136238

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Serine/threonine-protein kinase N1	B	81	Homo sapiens	Mutation(s): 0  Gene Names: PKN1, PKN, PRK1, PRKCL1, PAK1 EC: 2.7.11.13
Find proteins for Q16512 (Homo sapiens) Explore Q16512  Go to UniProtKB:  Q16512
NIH Common Fund Data Resources
PHAROS  Q16512 GTEx  ENSG00000123143

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
GCP	A	PHOSPHOMETHYLPHOSPHONIC ACID GUANYLATE ESTER C11 H18 N5 O13 P3 PHBDHXOBFUBCJD-KQYNXXCUSA-N
MG	A	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 25 
• Selection Criteria: structures with the lowest energy 
• OLDERADO: 2RMK Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2007-10-25 
• Released Date: 2007-11-13 
Deposition Author(s): Modha, R., Campbell, L.J., Nietlispach, D., Buhecha, H.R., Owen, D., Mott, H.R.

Revision History 

• Version 1.0: 2007-11-13
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Version format compliance