3DIN

Crystal structure of the protein-translocation complex formed by the SecY channel and the SecA ATPase

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 4.50 Å
  • R-Value Free: 0.303 
  • R-Value Work: 0.279 
  • R-Value Observed: 0.279 

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This is version 1.2 of the entry. See complete history. 


Literature

Structure of a complex of the ATPase SecA and the protein-translocation channel.

Zimmer, J., Nam, Y., Rapoport, T.A.

(2008) Nature 455: 936-943

  • DOI: 10.1038/nature07335
  • Primary Citation of Related Structures:  
    3DIN, 3DL8

  • PubMed Abstract: 

    • Most proteins are secreted from bacteria by the interaction of the cytoplasmic SecA ATPase with a membrane channel, formed by the heterotrimeric SecY complex. Here we report the crystal structure of SecA bound to the SecY complex, with a maximum resolution of 4 ...

    Most proteins are secreted from bacteria by the interaction of the cytoplasmic SecA ATPase with a membrane channel, formed by the heterotrimeric SecY complex. Here we report the crystal structure of SecA bound to the SecY complex, with a maximum resolution of 4.5 ångström (A), obtained for components from Thermotoga maritima. One copy of SecA in an intermediate state of ATP hydrolysis is bound to one molecule of the SecY complex. Both partners undergo important conformational changes on interaction. The polypeptide-cross-linking domain of SecA makes a large conformational change that could capture the translocation substrate in a 'clamp'. Polypeptide movement through the SecY channel could be achieved by the motion of a 'two-helix finger' of SecA inside the cytoplasmic funnel of SecY, and by the coordinated tightening and widening of SecA's clamp above the SecY pore. SecA binding generates a 'window' at the lateral gate of the SecY channel and it displaces the plug domain, preparing the channel for signal sequence binding and channel opening.

    Organizational Affiliation: 

    Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Protein translocase subunit secA A, B871Thermotoga maritima MSB8Mutation(s): 0 
Gene Names: secA, TM_1578
Membrane protein
Mpstruc		Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group: 
Sec, Translocase, and Insertase Proteins		Protein: 
SecYEG translocon in complex with SecA
Find proteins for Q9X1R4 (Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099))
Explore Q9X1R4 
Go to UniProtKB:  Q9X1R4
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Preprotein translocase subunit SecY C, F431Thermotoga maritima MSB8Mutation(s): 0 
Gene Names: secY, TM_1480
Membrane protein
Mpstruc		Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group: 
Sec, Translocase, and Insertase Proteins		Protein: 
SecYEG translocon in complex with SecA
Find proteins for Q9X1I9 (Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099))
Explore Q9X1I9 
Go to UniProtKB:  Q9X1I9
Protein Feature View
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Preprotein translocase subunit secE D, G65Thermotoga maritima MSB8Mutation(s): 0 
Gene Names: secE, TM_0452
Membrane protein
Mpstruc		Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group: 
Sec, Translocase, and Insertase Proteins		Protein: 
SecYEG translocon in complex with SecA
Find proteins for P35874 (Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099))
Explore P35874 
Go to UniProtKB:  P35874
Protein Feature View
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  • Reference Sequence
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Entity ID: 4
MoleculeChainsSequence LengthOrganismDetailsImage
Preprotein translocase subunit SecG E, H76Thermotoga sp. RQ2Mutation(s): 0 
Gene Names: secG, TRQ2_0456
Membrane protein
Mpstruc		Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group: 
Sec, Translocase, and Insertase Proteins		Protein: 
SecYEG translocon in complex with SecA
Find proteins for A0A0F6AK20 (Thermotoga sp. (strain RQ2))
Explore A0A0F6AK20 
Go to UniProtKB:  A0A0F6AK20
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ADP
Query on ADP
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A, B
ADENOSINE-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
XTWYTFMLZFPYCI-KQYNXXCUSA-N		 Ligand Interaction
BEF
Query on BEF
Download Ideal Coordinates CCD File 
A, B
BERYLLIUM TRIFLUORIDE ION
Be F3
OGIAHMCCNXDTIE-UHFFFAOYSA-K		 Ligand Interaction
MG
Query on MG
Download Ideal Coordinates CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N		 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 4.50 Å
  • R-Value Free: 0.303 
  • R-Value Work: 0.279 
  • R-Value Observed: 0.279 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 101.616α = 90
b = 156.003β = 90
c = 358.155γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PHASERphasing
SOLVEphasing
DMphasing
CNSrefinement
PDB_EXTRACTdata extraction

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-10-07
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Source and taxonomy, Version format compliance
  • Version 1.2: 2017-10-25
    Changes: Refinement description