2FSF

Escherichia coli SecA, the preprotein translocase dimeric ATPase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.213 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of dimeric SecA, the Escherichia coli preprotein translocase motor.

Papanikolau, Y.Papadovasilaki, M.Ravelli, R.B.McCarthy, A.A.Cusack, S.Economou, A.Petratos, K.

(2007) J.Mol.Biol. 366: 1545-1557

  • DOI: 10.1016/j.jmb.2006.12.049
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • SecA is the preprotein translocase ATPase subunit and a superfamily 2 (SF2) RNA helicase. Here we present the 2 A crystal structures of the Escherichia coli SecA homodimer in the apo form and in complex with ATP, ADP and adenosine 5'-[beta,gamma-imid ...

    SecA is the preprotein translocase ATPase subunit and a superfamily 2 (SF2) RNA helicase. Here we present the 2 A crystal structures of the Escherichia coli SecA homodimer in the apo form and in complex with ATP, ADP and adenosine 5'-[beta,gamma-imido]triphosphate (AMP-PNP). Each monomer contains the SF2 ATPase core (DEAD motor) built of two domains (nucleotide binding domain, NBD and intramolecular regulator of ATPase 2, IRA2), the preprotein binding domain (PBD), which is inserted in NBD and a carboxy-terminal domain (C-domain) linked to IRA2. The structures of the nucleotide complexes of SecA identify an interfacial nucleotide-binding cleft located between the two DEAD motor domains and residues critical for ATP catalysis. The dimer comprises two virtually identical protomers associating in an antiparallel fashion. Dimerization is mediated solely through extensive contacts of the DEAD motor domains leaving the C-domain facing outwards from the dimerization core. This dimerization mode explains the effect of functionally important mutations and is completely different from the dimerization models proposed for other SecA structures. The repercussion of these findings on translocase assembly and catalysis is discussed.


    Related Citations: 
    • Escherichia coli SecA truncated at its termini is functional and dimeric
      Karamanou, S.,Sianidis, G.,Gouridis, G.,Pozidis, C.,Papanikolau, Y.,Papanikou, E.,Economou, A.
      (2005) Febs Lett. 579: 1267


    Organizational Affiliation

    Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, PO Box 1385, 71110 Heraklion, Greece.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Preprotein translocase secA subunit
A, B
853Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: secA (azi, pea, prlD)
Find proteins for P10408 (Escherichia coli (strain K12))
Go to UniProtKB:  P10408
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.213 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 75.030α = 90.00
b = 90.171β = 100.48
c = 163.049γ = 90.00
Software Package:
Software NamePurpose
XSCALEdata scaling
CCP4data scaling
SHELXDphasing
SHARPphasing
PDB_EXTRACTdata extraction
REFMACrefinement
MOSFLMdata reduction
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-01-16
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance