1NF3

Structure of Cdc42 in a complex with the GTPase-binding domain of the cell polarity protein, Par6

Summary for 1NF3

• Entry DOI: 10.2210/pdb1nf3/pdb
• Descriptor: G25K GTP-binding protein, placental isoform, PAR-6B, MAGNESIUM ION, ... (5 entities in total)
• Functional Keywords: semi-crib motif, switch i and ii, pdz domain, gtpase binding domain, signaling protein
• Biological source: Homo sapiens (human); More
• Cellular location: Cell membrane; Lipid-anchor; Cytoplasmic side (Potential): P60953; Cytoplasm: Q9JK83
• Total number of polymer chains: 4
• Total formula weight: 72577.73

Authors

Garrard, S.M.,Capaldo, C.T.,Gao, L.,Rosen, M.K.,Macara, I.G.,Tomchick, D.R. (deposition date: 2002-12-12, release date: 2003-03-04, Last modification date: 2024-10-30)

Primary citation

Garrard, S.M.,Capaldo, C.T.,Gao, L.,Rosen, M.K.,Macara, I.G.,Tomchick, D.R.
Structure of Cdc42 in a complex with the GTPase-binding domain of the cell polarity protein, Par6
Embo J., 22:1125-1133, 2003

PubMed Abstract: Cdc42 is a small GTPase that is required for cell polarity establishment in eukaryotes as diverse as budding yeast and mammals. Par6 is also implicated in metazoan cell polarity establishment and asymmetric cell divisions. Cdc42.GTP interacts with proteins that contain a conserved sequence called a CRIB motif. Uniquely, Par6 possesses a semi-CRIB motif that is not sufficient for binding to Cdc42. An adjacent PDZ domain is also necessary and is required for biological effects of Par6. Here we report the crystal structure of a complex between Cdc42 and the Par6 GTPase-binding domain. The semi-CRIB motif forms a beta-strand that inserts between the four strands of Cdc42 and the three strands of the PDZ domain to form a continuous eight-stranded sheet. Cdc42 induces a conformational change in Par6, detectable by fluorescence resonance energy transfer spectroscopy. Nuclear magnetic resonance studies indicate that the semi-CRIB motif of Par6 is at least partially structured by the PDZ domain. The structure highlights a novel role for a PDZ domain as a structural scaffold.

PubMed: 12606577
DOI: 10.1093/emboj/cdg110

Experimental method

X-RAY DIFFRACTION (2.1 Å)