4NAM

1.7A structure of 5-Fluoro Tryptophan Labeled Protective Antigen (W206Y)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.179 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

(19)F nuclear magnetic resonance and crystallographic studies of 5-fluorotryptophan-labeled anthrax protective antigen and effects of the receptor on stability.

Chadegani, F.Lovell, S.Mullangi, V.Miyagi, M.Battaile, K.P.Bann, J.G.

(2014) Biochemistry 53: 690-701

  • DOI: 10.1021/bi401405s

  • PubMed Abstract: 
  • The anthrax protective antigen (PA) is an 83 kDa protein that is one of three protein components of the anthrax toxin, an AB toxin secreted by Bacillus anthracis. PA is capable of undergoing several structural changes, including oligomerization to ei ...

    The anthrax protective antigen (PA) is an 83 kDa protein that is one of three protein components of the anthrax toxin, an AB toxin secreted by Bacillus anthracis. PA is capable of undergoing several structural changes, including oligomerization to either a heptameric or octameric structure called the prepore, and at acidic pH a major conformational change to form a membrane-spanning pore. To follow these structural changes at a residue-specific level, we have conducted initial studies in which we have biosynthetically incorporated 5-fluorotryptophan (5-FTrp) into PA, and we have studied the influence of 5-FTrp labeling on the structural stability of PA and on binding to the host receptor capillary morphogenesis protein 2 (CMG2) using (19)F nuclear magnetic resonance (NMR). There are seven tryptophans in PA, but of the four domains in PA, only two contain tryptophans: domain 1 (Trp65, -90, -136, -206, and -226) and domain 2 (Trp346 and -477). Trp346 is of particular interest because of its proximity to the CMG2 binding interface, and because it forms part of the membrane-spanning pore. We show that the (19)F resonance of Trp346 is sensitive to changes in pH, consistent with crystallographic studies, and that receptor binding significantly stabilizes Trp346 to both pH and temperature. In addition, we provide evidence that suggests that resonances from tryptophans distant from the binding interface are also stabilized by the receptor. Our studies highlight the positive impact of receptor binding on protein stability and the use of (19)F NMR in gaining insight into structural changes in a high-molecular weight protein.


    Organizational Affiliation

    Department of Chemistry, Wichita State University , Wichita, Kansas 67260, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protective antigen
A
735Bacillus anthracisMutation(s): 1 
Gene Names: pagA (pag)
Find proteins for P13423 (Bacillus anthracis)
Go to UniProtKB:  P13423
Small Molecules
Ligands 1 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
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
FTR
Query on FTR
A
L-PEPTIDE LINKINGC11 H11 F N2 O2TRP
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.179 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 71.298α = 90.00
b = 93.954β = 90.00
c = 117.727γ = 90.00
Software Package:
Software NamePurpose
JDirectordata collection
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
PHASERphasing
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-01-22
    Type: Initial release
  • Version 1.1: 2014-12-24
    Type: Database references
  • Version 1.2: 2017-11-15
    Type: Refinement description