PDBsum entry 1q9c

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protein Protein-protein interface(s) links
Signaling protein PDB id
Protein chains
164 a.a. *
(+ 1 more) 172 a.a. *
* Residue conservation analysis
PDB id:
Name: Signaling protein
Title: Crystal structure of the histone domain of son of sevenless
Structure: Son of sevenless protein. Chain: a, b, c, d, e, f, g, h, i. Fragment: n-terminal histone domain. Synonym: sos-1. Engineered: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Gene: sos1. Expressed in: escherichia coli. Expression_system_taxid: 562.
Biol. unit: Nonamer (from PQS)
3.21Å     R-factor:   0.255     R-free:   0.292
Authors: H.Sondermann,S.M.Soisson,D.Bar-Sagi,J.Kuriyan
Key ref:
H.Sondermann et al. (2003). Tandem histone folds in the structure of the N-terminal segment of the ras activator Son of Sevenless. Structure, 11, 1583-1593. PubMed id: 14656442 DOI: 10.1016/j.str.2003.10.015
24-Aug-03     Release date:   09-Dec-03    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
Q07889  (SOS1_HUMAN) -  Son of sevenless homolog 1
1333 a.a.
164 a.a.*
Protein chains
Pfam   ArchSchema ?
Q07889  (SOS1_HUMAN) -  Son of sevenless homolog 1
1333 a.a.
172 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 2 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     nucleus   2 terms 
  Biochemical function     DNA binding     2 terms  


DOI no: 10.1016/j.str.2003.10.015 Structure 11:1583-1593 (2003)
PubMed id: 14656442  
Tandem histone folds in the structure of the N-terminal segment of the ras activator Son of Sevenless.
H.Sondermann, S.M.Soisson, D.Bar-Sagi, J.Kuriyan.
The Ras activator Son of Sevenless (Sos) contains a Cdc25 homology domain, responsible for nucleotide exchange, as well as Dbl/Pleckstrin homology (DH/PH) domains. We have determined the crystal structure of the N-terminal segment of human Sos1 (residues 1-191) and show that it contains two tandem histone folds. While the N-terminal domain is monomeric in solution, its structure is surprisingly similar to that of histone dimers, with both subunits of the histone "dimer" being part of the same peptide chain. One histone fold corresponds to the region of Sos that is clearly similar in sequence to histones (residues 91-191), whereas the other is formed by residues in Sos (1-90) that are unrelated in sequence to histones. Residues that form a contiguous patch on the surface of the histone domain of Sos are conserved from C. elegans to humans, suggesting a potential role for this domain in protein-protein interactions.
  Selected figure(s)  
Figure 4.
Figure 4. Comparison of the Histone Domain of Sos with the Structures of Various Histone ProteinsSuperpositions were generated by TOP3D (Lu, 2000). The histone domain of Sos is shown in gray. The darker gray represents the C-terminal H2A homology region. Rms deviations for the Ca backbone atoms between structures being compared are indicated. Alignment with the nucleosomal core histone dimers H2A/H2B (A) and H3/H4 (B) are shown. H2A is colored in light green, H2B in dark green. H3 and H4 are shown in orange and red, respectively (PDB code: 1KX5; Davey et al., 2002). (C) Alignment with Methanopyrus kandleri histone (PDB code: 1F1E; Fahrner et al., 2001).
  The above figure is reprinted by permission from Cell Press: Structure (2003, 11, 1583-1593) copyright 2003.  
  Figure was selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
21111786 A.Fernández-Medarde, and E.Santos (2011).
The RasGrf family of mammalian guanine nucleotide exchange factors.
  Biochim Biophys Acta, 1815, 170-188.  
20133694 K.K.Yadav, and D.Bar-Sagi (2010).
Allosteric gating of Son of sevenless activity by the histone domain.
  Proc Natl Acad Sci U S A, 107, 3436-3440.  
20030748 M.Tumurkhuu, M.Saitoh, A.Sato, K.Takahashi, M.Mimaki, J.Takita, K.Takeshita, T.Hama, A.Oka, and M.Mizuguchi (2010).
Comprehensive genetic analysis of overlapping syndromes of RAS/RAF/MEK/ERK pathway.
  Pediatr Int, 52, 557-562.  
19218565 P.Walker, D.Doenecke, and J.Kahle (2009).
Importin 13 Mediates Nuclear Import of Histone Fold-containing Chromatin Accessibility Complex Heterodimers.
  J Biol Chem, 284, 11652-11662.  
18454158 J.Gureasko, W.J.Galush, S.Boykevisch, H.Sondermann, D.Bar-Sagi, J.T.Groves, and J.Kuriyan (2008).
Membrane-dependent signal integration by the Ras activator Son of sevenless.
  Nat Struct Mol Biol, 15, 452-461.  
17143285 A.E.Roberts, T.Araki, K.D.Swanson, K.T.Montgomery, T.A.Schiripo, V.A.Joshi, L.Li, Y.Yassin, A.M.Tamburino, B.G.Neel, and R.S.Kucherlapati (2007).
Germline gain-of-function mutations in SOS1 cause Noonan syndrome.
  Nat Genet, 39, 70-74.  
16345076 L.Mariño-Ramírez, B.Hsu, A.D.Baxevanis, and D.Landsman (2006).
The Histone Database: a comprehensive resource for histones and histone fold-containing proteins.
  Proteins, 62, 838-842.  
16760435 N.Zarich, J.L.Oliva, N.Martínez, R.Jorge, A.Ballester, S.Gutiérrez-Eisman, S.García-Vargas, and J.M.Rojas (2006).
Grb2 is a negative modulator of the intrinsic Ras-GEF activity of hSos1.
  Mol Biol Cell, 17, 3591-3597.  
16247600 C.Greco, E.Sacco, M.Vanoni, and L.De Gioia (2005).
Identification and in silico analysis of a new group of double-histone fold-containing proteins.
  J Mol Model, 12, 76-84.  
16351741 C.Greco, P.Fantucci, and L.De Gioia (2005).
In silico functional characterization of a double histone fold domain from the Heliothis zea virus 1.
  BMC Bioinformatics, 6, S15.  
15507210 H.Sondermann, S.M.Soisson, S.Boykevisch, S.S.Yang, D.Bar-Sagi, and J.Kuriyan (2004).
Structural analysis of autoinhibition in the Ras activator Son of sevenless.
  Cell, 119, 393-405.
PDB codes: 1xd2 1xd4 1xdv
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB codes are shown on the right.