Structural and biophysical properties of FopA, a major outer membrane protein of Francisella tularensis.

Nagaratnam N, Martin-Garcia JM, Yang JH, Goode MR, Ketawala G, Craciunescu FM, Zook JD, Sonowal M, Williams D, Grant TD, Fromme R, Hansen DT, Fromme P, PLoS One 17(8):e0267370 (2022) Europe PMC

SASDLP2 – Outer membrane associated protein, FopA dimer in Tris-HCl, NaCl and n-Dodecyl beta-D-maltoside

Francisella tularensis outer membrane protein A
MWexperimental 88 kDa
MWexpected 80 kDa
VPorod 330 nm3
log I(s) 1.39×10-4 1.39×10-5 1.39×10-6 1.39×10-7
Francisella tularensis outer membrane protein A small angle scattering data  s, nm-1
ln I(s)
Francisella tularensis outer membrane protein A Guinier plot ln 1.39×10-4 Rg: 4.4 nm 0 (4.4 nm)-2 s2
(sRg)2I(s)/I(0)
Francisella tularensis outer membrane protein A Kratky plot 1.104 0 √3 sRg
p(r)
Francisella tularensis outer membrane protein A pair distance distribution function Rg: 4.5 nm 0 Dmax: 16 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Synchrotron SAXS data from solutions of FopA in 20 mM Tris, 150 mM NaCl, 0.05% B-DDM, pH 7.5 were collected on the BioCAT 18ID beam line at the Advanced Photon Source (APS), Argonne National Laboratory (Lemont, IL, USA) using a Pilatus3 X 1M detector at a sample-detector distance of 3.5 m and at a wavelength of λ = 0.1033 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 5.00 mg/ml was measured at 20 °C. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

Francisella tularensis outer membrane protein A (FopA)
Mol. type   Protein
Organism   Francisella tularensis subsp. tularensis (strain SCHU S4 / Schu 4)
Olig. state   Dimer
Mon. MW   40.2 kDa
 
UniProt   Q5NH85 (24-393)
Sequence   FASTA