1OX8

Crystal structure of SspB


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.248 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural basis of degradation signal recognition by SspB, a specificity-enhancing factor for the ClpXP proteolytic machine

Song, H.K.Eck, M.J.

(2003) Mol.Cell 12: 75-86

  • Primary Citation of Related Structures:  1OX9

  • PubMed Abstract: 
  • In prokaryotes, incomplete or misfolded polypeptides emanating from a stalled ribosome are marked for degradation by the addition of an 11 residue peptide (AANDENYALAA) to their C terminus. Substrates containing this conserved degradation signal, the ...

    In prokaryotes, incomplete or misfolded polypeptides emanating from a stalled ribosome are marked for degradation by the addition of an 11 residue peptide (AANDENYALAA) to their C terminus. Substrates containing this conserved degradation signal, the SsrA tag, are targeted to specific proteases including ClpXP and ClpAP. SspB was originally characterized as a stringent starvation protein and has been found to bind specifically to SsrA-tagged proteins and to enhance recognition of these proteins by the ClpXP degradation machine. Here, we report the crystal structures of SspB alone and in complex with an SsrA peptide. Unexpectedly, SspB exhibits a fold found in Sm-family RNA binding proteins. The dimeric SspB structures explain the key determinants for recognition of the SsrA tag and define a hydrophobic channel that may bind unfolded substrates.


    Organizational Affiliation

    Department of Cancer Biology, Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Stringent starvation protein B
A, B
107Escherichia coli (strain K12)Gene Names: sspB
Find proteins for P0AFZ3 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AFZ3
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.248 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 60.116α = 90.00
b = 60.116β = 90.00
c = 187.984γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
SCALEPACKdata scaling
DMmodel building
CNSrefinement
HKL-2000data reduction
DMphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2003-04-01 
  • Released Date: 2003-08-26 
  • Deposition Author(s): Song, H.K., Eck, M.J.

Revision History 

  • Version 1.0: 2003-08-26
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Source and taxonomy, Version format compliance