1bkd
From Proteopedia
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COMPLEX OF HUMAN H-RAS WITH HUMAN SOS-1
Contents |
Overview
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.
Disease
Known diseases associated with this structure: Bladder cancer, somatic OMIM:[190020], Costello syndrome OMIM:[190020], Fibromatosis, gingival OMIM:[182530], Noonan syndrome 4 OMIM:[182530], Thyroid carcinoma, follicular, somatic OMIM:[190020]
About this Structure
1BKD is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The structural basis of the activation of Ras by Sos., Boriack-Sjodin PA, Margarit SM, Bar-Sagi D, Kuriyan J, Nature. 1998 Jul 23;394(6691):337-43. PMID:9690470
Page seeded by OCA on Thu Feb 21 11:56:14 2008
