1YY7

Crystal structure of stringent starvation protein A (SspA), an RNA polymerase-associated transcription factor


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.02 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.179 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural basis for the function of stringent starvation protein A as a transcription factor

Hansen, A.-M.Gu, Y.Li, M.Andrykovitch, M.Waugh, D.S.Jin, D.J.Ji, X.

(2005) J.Biol.Chem. 280: 17380-17391

  • DOI: 10.1074/jbc.M501444200

  • PubMed Abstract: 
  • Stringent starvation protein A (SspA) of Escherichia coli is an RNA polymerase-associated transcriptional activator for the lytic development of phage P1 and is essential for stationary phase-induced acid tolerance of E. coli. We report the crystal s ...

    Stringent starvation protein A (SspA) of Escherichia coli is an RNA polymerase-associated transcriptional activator for the lytic development of phage P1 and is essential for stationary phase-induced acid tolerance of E. coli. We report the crystal structure of Yersinia pestis SspA, which is 83% identical to E. coli SspA in amino acid sequence and is functionally complementary in supporting the lytic growth of phage P1 and acid resistance of an E. coli sspA mutant. The structure reveals that SspA assumes the characteristic fold of glutathione S-transferase (GST). However, SspA lacks GST activity and does not bind glutathione. Three regions of SspA are flexible, the N and C termini and the alpha2-helix. The structure also reveals a conserved surface-exposed pocket composed of residues from a loop between helices alpha3 and alpha4. The functional roles of these structural features were investigated by assessing the ability of deletion and site-directed mutants to confer acid resistance of E. coli and to activate transcription from a phage P1 late promoter, thereby supporting the lytic growth of phage P1. The results indicate that the flexible regions are not critical for SspA function, whereas the surface pocket is important for both transcriptional activation of the phage P1 late promoter and acid resistance of E. coli. The size, shape, and property of the pocket suggest that it mediates protein-protein interactions. SspA orthologs from Y. pestis, Vibrio cholerae, and Pseudomonas aeruginosa are all functional in acid resistance of E. coli, whereas only Y. pestis SspA supports phage P1 growth.


    Organizational Affiliation

    Transcription Control Section, Gene Regulation and Chromosome Biology Laboratory, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
stringent starvation protein A
A, B
213Yersinia pestisMutation(s): 0 
Gene Names: pog
Find proteins for A0A384KMD8 (Yersinia pestis)
Go to UniProtKB:  A0A384KMD8
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CIT
Query on CIT

Download SDF File 
Download CCD File 
B
CITRIC ACID
C6 H8 O7
KRKNYBCHXYNGOX-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.02 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.179 
  • Space Group: P 65 2 2
Unit Cell:
Length (Å)Angle (°)
a = 100.412α = 90.00
b = 100.412β = 90.00
c = 181.890γ = 120.00
Software Package:
Software NamePurpose
CNSrefinement
SOLVEphasing
SHARPphasing
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-03-01
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance