3QYX: Crystal Structure Of Mycobacterium Tuberculosis Espr In Complex With A Small Dna Fragment

Citation:
Abstract
The human pathogen Mycobacterium tuberculosis requires the ESX-1 secretion system for full virulence. EspR plays a key role in ESX-1 regulation via direct binding and transcriptional activation of the espACD operon. Here, we describe the crystal structures of EspR, a C-terminally truncated form, EspRDelta10, as well as an EspR-DNA complex. EspR forms a dimer with each monomer containing an N-terminal helix-turn-helix DNA binding motif and an atypical C-terminal dimerization domain. Structural studies combined with footprinting experiments, atomic force microscopy and molecular dynamic simulations allow us to propose a model in which a dimer of EspR dimers is the minimal functional unit with two subunits binding two consecutive major grooves. The other two DNA binding domains are thus free to form higher-order oligomers and to bridge distant DNA sites in a cooperative way. These features are reminiscent of nucleoid-associated proteins and suggest a more general regulatory role for EspR than was previously suspected.
PDB ID: 3QYXDownload
MMDB ID: 93564
PDB Deposition Date: 2011/3/4
Updated in MMDB: 2011/11
Experimental Method:
x-ray diffraction
Resolution: 3.75  Å
Source Organism:
Mycobacterium tuberculosis H37Rv
Similar Structures:
Biological Unit for 3QYX: pentameric; determined by author
Molecular Components in 3QYX
Label Count Molecule
Proteins (4 molecules)
4
Esx-1 Secretion-associated Regulator Espr
Molecule annotation
Nucleotide(1 molecule)
1
5'-d(*a*cp*gp*cp*cp*gp*ap*ap*tp*c)-3'
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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