2P2L

Rac1-GDP-Zinc Complex

Summary for 2P2L

• Entry DOI: 10.2210/pdb2p2l/pdb
• Descriptor: Ras-related C3 botulinum toxin substrate 1, ZINC ION, GUANOSINE-5'-DIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: rho family gtpase, unknown function
• Biological source: Homo sapiens (human)
• Cellular location: Cell membrane ; Lipid-anchor ; Cytoplasmic side : P63000
• Total number of polymer chains: 3
• Total formula weight: 64220.23

Authors

Prehna, G.,Stebbins, C.E. (deposition date: 2007-03-07, release date: 2007-05-01, Last modification date: 2023-08-30)

Primary citation

Prehna, G.,Stebbins, C.E.
A Rac1-GDP trimer complex binds zinc with tetrahedral and octahedral coordination, displacing magnesium.
Acta Crystallogr.,Sect.D, 63:628-635, 2007

PubMed Abstract: The Rho family of small GTPases represent well characterized signaling molecules that regulate many cellular functions such as actin cytoskeletal arrangement and the cell cycle by acting as molecular switches. A Rac1-GDP-Zn complex has been crystallized in space group P3(2)21 and its crystal structure has been solved at 1.9 A resolution. These trigonal crystals reveal the unexpected ability of Rac1 to coordinate Zn atoms in a tetrahedral fashion by use of its biologically relevant switch I and switch II regions. Upon coordination of zinc, the switch I region is stabilized in the GDP-bound conformation and contributes to a Rac1 trimer in the asymmetric unit. Zinc coordination causes switch II to adopt a novel conformation with a symmetry-related molecule. Additionally, zinc was found to displace magnesium from its octahedral coordination at switch I, although GDP binding remained stable. This structure represents the first reported Rac1-GDP-Zn complex, which further underscores the conformational flexibility and versatility of the small GTPase switch regions.

PubMed: 17452788
DOI: 10.1107/S0907444907010888

Experimental method

X-RAY DIFFRACTION (1.9 Å)