2RMK

Rac1/PRK1 Complex

Summary for 2RMK

• Entry DOI: 10.2210/pdb2rmk/pdb
• NMR Information: BMRB: 11010
• Descriptor: Ras-related C3 botulinum toxin substrate 1, Serine/threonine-protein kinase N1, MAGNESIUM ION, ... (5 entities in total)
• Functional Keywords: g protein, effector, adp-ribosylation, alternative splicing, gtp-binding, lipoprotein, membrane, methylation, nucleotide-binding, polymorphism, prenylation, atp-binding, cytoplasm, kinase, phosphorylation, serine/threonine-protein kinase, transferase, membrane protein-transferase complex, membrane protein/transferase
• Biological source: Homo sapiens (human); More
• Cellular location: Cell membrane; Lipid-anchor; Cytoplasmic side (By similarity): P63000; Cytoplasm: Q16512
• Total number of polymer chains: 2
• Total formula weight: 31026.07

Authors

Modha, R.,Campbell, L.J.,Nietlispach, D.,Buhecha, H.R.,Owen, D.,Mott, H.R. (deposition date: 2007-10-25, release date: 2007-11-13, Last modification date: 2024-05-29)

Primary citation

Modha, R.,Campbell, L.J.,Nietlispach, D.,Buhecha, H.R.,Owen, D.,Mott, H.R.
The Rac1 Polybasic Region Is Required for Interaction with Its Effector PRK1
J.Biol.Chem., 283:1492-1500, 2008

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.

PubMed: 18006505
DOI: 10.1074/jbc.M706760200

Experimental method

SOLUTION NMR