3MHZ

1.7A structure of 2-fluorohistidine labeled Protective Antigen


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.192 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Evidence that histidine protonation of receptor-bound anthrax protective antigen is a trigger for pore formation.

Wimalasena, D.S.Janowiak, B.E.Lovell, S.Miyagi, M.Sun, J.Zhou, H.Hajduch, J.Pooput, C.Kirk, K.L.Battaile, K.P.Bann, J.G.

(2010) Biochemistry 49: 6973-6983

  • DOI: 10.1021/bi100647z

  • PubMed Abstract: 
  • The protective antigen (PA) component of the anthrax toxin forms pores within the low pH environment of host endosomes through mechanisms that are poorly understood. It has been proposed that pore formation is dependent on histidine protonation. In p ...

    The protective antigen (PA) component of the anthrax toxin forms pores within the low pH environment of host endosomes through mechanisms that are poorly understood. It has been proposed that pore formation is dependent on histidine protonation. In previous work, we biosynthetically incorporated 2-fluorohistidine (2-FHis), an isosteric analogue of histidine with a significantly reduced pK(a) ( approximately 1), into PA and showed that the pH-dependent conversion from the soluble prepore to a pore was unchanged. However, we also observed that 2-FHisPA was nonfunctional in the ability to mediate cytotoxicity of CHO-K1 cells by LF(N)-DTA and was defective in translocation through planar lipid bilayers. Here, we show that the defect in cytotoxicity is due to both a defect in translocation and, when bound to the host cellular receptor, an inability to undergo low pH-induced pore formation. Combining X-ray crystallography with hydrogen-deuterium (H-D) exchange mass spectrometry, our studies lead to a model in which hydrogen bonds to the histidine ring are strengthened by receptor binding. The combination of both fluorination and receptor binding is sufficient to block low pH-induced pore formation.


    Organizational Affiliation

    Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protective antigen
A
735Bacillus anthracisMutation(s): 0 
Gene Names: pagA (pag)
Find proteins for P13423 (Bacillus anthracis)
Go to UniProtKB:  P13423
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
PG4
Query on PG4

Download SDF File 
Download CCD File 
A
TETRAETHYLENE GLYCOL
C8 H18 O5
UWHCKJMYHZGTIT-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
2HF
Query on 2HF
A
L-PEPTIDE LINKINGC6 H9 F N3 O2HIS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.192 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 71.368α = 90.00
b = 93.975β = 90.00
c = 119.115γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
HKL-2000data reduction
REFMACrefinement
PDB_EXTRACTdata extraction
SCALEPACKdata scaling
MOLREPphasing
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-08-11
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-08
    Type: Refinement description