Biological Assembly 1  

 3D View: Structure

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly 2  

 3D View: Structure

Global Symmetry: Dihedral - D2  (3D View)
Global Stoichiometry: Homo 4-mer - A4 

Biological assembly 2 generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 206.93 kDa 
• Atom Count: 14209 
• Modelled Residue Count: 1677 
• Deposited Residue Count: 1844 
• Unique protein chains: 1

1NL3

CRYSTAL STRUCTURE OF THE SECA PROTEIN TRANSLOCATION ATPASE FROM MYCOBACTERIUM TUBERCULOSIS in APO FORM

• DOI: 10.2210/pdb1NL3/pdb

• Classification: PROTEIN TRANSPORT
• Organism(s): Mycobacterium tuberculosis
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2003-01-06 Released: 2003-03-04 
• Deposition Author(s): Sharma, V., Arockiasamy, A., Ronning, D.R., Savva, C.G., Holzenburg, A., Braunstein, M., Jacobs Jr., W.R., Sacchettini, J.C., TB Structural Genomics Consortium (TBSGC)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.259 
• R-Value Work: 0.193 
• R-Value Observed: 0.196 

Literature

Crystal Structure of M. tuberculosis SecA, A Preprotein Translocating ATPase

Sharma, V., Arockiasamy, A., Ronning, D.R., Savva, C.G., Holzenburg, A., Braunstein, M., Jacobs Jr., W.R., Sacchettini, J.C.

(2003) Proc Natl Acad Sci U S A 100: 2243-2248

• PubMed: 12606717 
• DOI: 10.1073/pnas.0538077100
• Primary Citation of Related Structures:  
  1NKT, 1NL3


• PubMed Abstract: 
  

In bacteria, the majority of exported proteins are translocated by the Sec system, which recognizes the signal sequence of a preprotein and uses ATP and the proton motive force to mediate protein translocation across the cytoplasmic membrane. SecA is an essential protein component of this system, containing the molecular motor that facilitates translocation. Here we report the three-dimensional structure of the SecA protein of Mycobacterium tuberculosis. Each subunit of the homodimer contains a "motor" domain and a translocation domain. The structure predicts that SecA can interact with the SecYEG pore and function as a molecular ratchet that uses ATP hydrolysis for physical movement of the preprotein. Knowledge of this structure provides a framework for further elucidation of the translocation process.

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Organizational Affiliation: 

Center for Structural Biology, Institute of Biosciences and Technology, Houston, TX 77030, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PREPROTEIN TRANSLOCASE SECA 1 SUBUNIT	A, B	922	Mycobacterium tuberculosis	Mutation(s): 0  Gene Names: SECA1 OR SECA OR RV3240C
UniProt
Find proteins for P9WGP5 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)) Explore P9WGP5  Go to UniProtKB:  P9WGP5

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.259 
• R-Value Work: 0.193 
• R-Value Observed: 0.196 
• Space Group: P 6₂ 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 206.196	α = 90
b = 206.196	β = 90
c = 295.412	γ = 120

Software Package:

Software Name	Purpose
REFMAC	refinement
HKL-2000	data reduction
SCALEPACK	data scaling
SHARP	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2003-01-06 
• Released Date: 2003-03-04 
Deposition Author(s): Sharma, V., Arockiasamy, A., Ronning, D.R., Savva, C.G., Holzenburg, A., Braunstein, M., Jacobs Jr., W.R., Sacchettini, J.C., TB Structural Genomics Consortium (TBSGC)

Revision History  

• Version 1.0: 2003-03-04
  Type: Initial release
  
• Version 1.1: 2008-04-29
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance