1BKD

COMPLEX OF HUMAN H-RAS WITH HUMAN SOS-1

Summary for 1BKD

• Entry DOI: 10.2210/pdb1bkd/pdb
• Descriptor: H-RAS, SON OF SEVENLESS-1 (3 entities in total)
• Functional Keywords: complex (oncogene protein-exchange factor), small gtpase, exchange factor, complex(oncogene protein-exchange factor) complex, complex(oncogene protein/exchange factor)
• Biological source: Homo sapiens (human); More
• Cellular location: Cell membrane; Lipid-anchor; Cytoplasmic side: P01112
• Total number of polymer chains: 2
• Total formula weight: 74894.29

Authors

Boriack-Sjodin, P.A.,Margarit, S.M.,Sagi, D.B.,Kuriyan, J. (deposition date: 1998-07-06, release date: 1999-01-13, Last modification date: 2024-02-07)

Primary citation

Boriack-Sjodin, P.A.,Margarit, S.M.,Bar-Sagi, D.,Kuriyan, J.
The structural basis of the activation of Ras by Sos.
Nature, 394:337-343, 1998

PubMed Abstract: The crystal structure of human H-Ras complexed with the Ras guanine-nucleotide-exchange-factor region of the Son of sevenless (Sos) protein has been determined at 2.8 A resolution. The normally tight interaction of nucleotides with Ras is disrupted by Sos in two ways. First, the insertion into Ras of an alpha-helix from Sos results in the displacement of the Switch 1 region of Ras, opening up the nucleotide-binding site. Second, side chains presented by this helix and by a distorted conformation of the Switch 2 region of Ras alter the chemical environment of the binding site for the phosphate groups of the nucleotide and the associated magnesium ion, so that their binding is no longer favoured. Sos does not impede the binding sites for the base and the ribose of GTP or GDP, so the Ras-Sos complex adopts a structure that allows nucleotide release and rebinding.

PubMed: 9690470
DOI: 10.1038/28548

Experimental method

X-RAY DIFFRACTION (2.8 Å)