Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Cyclic - C4  (3D View)
Global Stoichiometry: Hetero 8-mer - A4B4 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 74.89 kDa 
• Atom Count: 5010 
• Modelled Residue Count: 605 
• Deposited Residue Count: 643 
• Unique protein chains: 2

1BKD

COMPLEX OF HUMAN H-RAS WITH HUMAN SOS-1

• DOI: 10.2210/pdb1BKD/pdb

• Classification: COMPLEX(ONCOGENE PROTEIN/EXCHANGE FACTOR)
• Organism(s): Homo sapiens
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 1998-07-06 Released: 1999-01-13 
• Deposition Author(s): Boriack-Sjodin, P.A., Margarit, S.M., Sagi, D.B., Kuriyan, J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.281 
• R-Value Work: 0.222 
• R-Value Observed: 0.222 

Literature

The structural basis of the activation of Ras by Sos.

Boriack-Sjodin, P.A., Margarit, S.M., Bar-Sagi, D., Kuriyan, J.

(1998) Nature 394: 337-343

• PubMed: 9690470 
• DOI: 10.1038/28548
• Primary Citation of Related Structures:  
  1BKD


• 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.

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Organizational Affiliation: 

Laboratory of Molecular Biophysics, The Rockefeller University, New York, New York 10021, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
H-RAS	A [auth R]	166	Homo sapiens	Mutation(s): 0  Gene Names: HRAS, HRAS1 EC: 3.6.5.2
Find proteins for P01112 (Homo sapiens) Explore P01112  Go to UniProtKB:  P01112
NIH Common Fund Data Resources
PHAROS:  P01112 GTEx:  ENSG00000174775

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
SON OF SEVENLESS-1	B [auth S]	477	Homo sapiens	Mutation(s): 0  Gene Names: SOS1
Find proteins for Q07889 (Homo sapiens) Explore Q07889  Go to UniProtKB:  Q07889
NIH Common Fund Data Resources
PHAROS:  Q07889 GTEx:  ENSG00000115904

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.281 
• R-Value Work: 0.222 
• R-Value Observed: 0.222 
• Space Group: I 4 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 142.7	α = 90
b = 142.7	β = 90
c = 207.9	γ = 90

Software Package:

Software Name	Purpose
CNS	refinement
DENZO	data reduction
SCALEPACK	data scaling
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1998-07-06 
• Released Date: 1999-01-13 
Deposition Author(s): Boriack-Sjodin, P.A., Margarit, S.M., Sagi, D.B., Kuriyan, J.

Revision History  

• Version 1.0: 1999-01-13
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance