4NQW

Structure of Mycobacterium tuberculosis extracytoplasmic function sigma factor SigK in complex with the cytosolic domain of its cognate anti-sigma factor RskA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural basis for the redox sensitivity of the Mycobacterium tuberculosis SigK-RskA sigma-anti-sigma complex

Shukla, J.Gupta, R.Thakur, K.G.Gokhale, R.Gopal, B.

(2014) Acta Crystallogr.,Sect.D 70: 1026-1036

  • DOI: 10.1107/S1399004714000121

  • PubMed Abstract: 
  • The host-pathogen interactions in Mycobacterium tuberculosis infection are significantly influenced by redox stimuli and alterations in the levels of secreted antigens. The extracytoplasmic function (ECF) σ factor σ(K) governs the transcription of th ...

    The host-pathogen interactions in Mycobacterium tuberculosis infection are significantly influenced by redox stimuli and alterations in the levels of secreted antigens. The extracytoplasmic function (ECF) σ factor σ(K) governs the transcription of the serodominant antigens MPT70 and MPT83. The cellular levels of σ(K) are regulated by the membrane-associated anti-σ(K) (RskA) that localizes σ(K) in an inactive complex. The crystal structure of M. tuberculosis σ(K) in complex with the cytosolic domain of RskA (RskAcyto) revealed a disulfide bridge in the -35 promoter-interaction region of σ(K). Biochemical experiments reveal that the redox potential of the disulfide-forming cysteines in σ(K) is consistent with its role as a sensor. The disulfide bond in σ(K) influences the stability of the σ(K)-RskAcyto complex but does not interfere with σ(K)-promoter DNA interactions. It is noted that these disulfide-forming cysteines are conserved across homologues, suggesting that this could be a general mechanism for redox-sensitive transcription regulation.


    Organizational Affiliation

    Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ECF RNA polymerase sigma factor SigK
A
204Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)Mutation(s): 0 
Gene Names: sigK
Find proteins for P9WGH7 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Go to UniProtKB:  P9WGH7
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Anti-sigma-K factor RskA
B
80Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)Mutation(s): 0 
Gene Names: rskA
Find proteins for P9WGX5 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Go to UniProtKB:  P9WGX5
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CD
Query on CD

Download SDF File 
Download CCD File 
A, B
CADMIUM ION
Cd
WLZRMCYVCSSEQC-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.205 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 57.390α = 90.00
b = 57.390β = 90.00
c = 150.870γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
MAR345dtbdata collection
SOLVEphasing
REFMACrefinement
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2013-11-25 
  • Released Date: 2014-01-22 
  • Deposition Author(s): Shukla, J.K., Gopal, B.
  • This entry supersedes: 3VDO

Revision History 

  • Version 1.0: 2014-01-22
    Type: Initial release
  • Version 1.1: 2014-04-16
    Type: Database references