3PMC

Crystal structure of the sporulation inhibitor pXO2-61 from Bacillus anthracis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.49 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.174 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural Insights into Inhibition of Bacillus anthracis Sporulation by a Novel Class of Non-heme Globin Sensor Domains.

Stranzl, G.R.Santelli, E.Bankston, L.A.La Clair, C.Bobkov, A.Schwarzenbacher, R.Godzik, A.Perego, M.Grynberg, M.Liddington, R.C.

(2011) J.Biol.Chem. 286: 8448-8458

  • DOI: 10.1074/jbc.M110.207126
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Pathogenesis by Bacillus anthracis requires coordination between two distinct activities: plasmid-encoded virulence factor expression (which protects vegetative cells from immune surveillance during outgrowth and replication) and chromosomally encode ...

    Pathogenesis by Bacillus anthracis requires coordination between two distinct activities: plasmid-encoded virulence factor expression (which protects vegetative cells from immune surveillance during outgrowth and replication) and chromosomally encoded sporulation (required only during the final stages of infection). Sporulation is regulated by at least five sensor histidine kinases that are activated in response to various environmental cues. One of these kinases, BA2291, harbors a sensor domain that has ∼35% sequence identity with two plasmid proteins, pXO1-118 and pXO2-61. Because overexpression of pXO2-61 (or pXO1-118) inhibits sporulation of B. anthracis in a BA2291-dependent manner, and pXO2-61 expression is strongly up-regulated by the major virulence gene regulator, AtxA, it was suggested that their function is to titrate out an environmental signal that would otherwise promote untimely sporulation. To explore this hypothesis, we determined crystal structures of both plasmid-encoded proteins. We found that they adopt a dimeric globin fold but, most unusually, do not bind heme. Instead, they house a hydrophobic tunnel and hydrophilic chamber that are occupied by fatty acid, which engages a conserved arginine and chloride ion via its carboxyl head group. In vivo, these domains may therefore recognize changes in fatty acid synthesis, chloride ion concentration, and/or pH. Structure-based comparisons with BA2291 suggest that it binds ligand and dimerizes in an analogous fashion, consistent with the titration hypothesis. Analysis of newly sequenced bacterial genomes points to the existence of a much broader family of non-heme, globin-based sensor domains, with related but distinct functionalities, that may have evolved from an ancestral heme-linked globin.


    Organizational Affiliation

    Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, La Jolla, California 92037, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Uncharacterized protein pXO2-61/BXB0075/GBAA_pXO2_0075
A, B
139Bacillus anthracisMutation(s): 0 
Find proteins for Q9RMX2 (Bacillus anthracis)
Go to UniProtKB:  Q9RMX2
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
IOD
Query on IOD

Download SDF File 
Download CCD File 
A, B
IODIDE ION
I
XMBWDFGMSWQBCA-UHFFFAOYSA-M
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
A, B
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.49 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.174 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 44.110α = 90.00
b = 62.620β = 90.00
c = 124.760γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-01-19
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance