Structural Insights of Shigella Translocator IpaB and Its Chaperone IpgC in Solution

Ferrari M, Charova S, Sansonetti P, Mylonas E, Gazi A, Frontiers in Cellular and Infection Microbiology 11 (2021) DOI

SASDKR9 – The chaperone protein IpgC/invasin IpaB heterodimer complex from Shigella flexneri

T3SS Chaperone protein IpgC
Invasin IpaB
MWI(0) 65 kDa
MWexpected 82 kDa
VPorod 165 nm3
log I(s) 1.72×102 1.72×101 1.72×100 1.72×10-1
T3SS Chaperone protein IpgC Invasin IpaB small angle scattering data  s, nm-1
ln I(s)
T3SS Chaperone protein IpgC Invasin IpaB Guinier plot ln 1.73×102 Rg: 3.9 nm 0 (3.9 nm)-2 s2
(sRg)2I(s)/I(0)
T3SS Chaperone protein IpgC Invasin IpaB Kratky plot 1.104 0 3 sRg
p(r)
T3SS Chaperone protein IpgC Invasin IpaB pair distance distribution function Rg: 4.0 nm 0 Dmax: 14 nm

Data validation


Fits and models


log I(s)
 s, nm-1
T3SS Chaperone protein IpgC Invasin IpaB EOM/RANCH model

Synchrotron SAXS data from solutions of the IpgC/IpaB heterodimer complex in 20 mM HEPES, 100 mM NaCl, pH 7.4 were collected on the BM29 beam line at the ESRF (Grenoble, France) using a Pilatus 1M detector at a sample-detector distance of 2.8 m and at a wavelength of λ = 0.09199 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). Solute concentrations ranging between 0.6 and 5.5 mg/ml were measured at 10°C. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted. The low angle data collected at lower concentrations were extrapolated to infinite dilution and merged with the higher concentration data to yield the final composite scattering curve.

T3SS Chaperone protein IpgC (IpgC)
Mol. type   Protein
Organism   Shigella flexneri
Olig. state   Monomer
Mon. MW   19.6 kDa
 
UniProt   P0A2U4 (2-155)
Sequence   FASTA
 
Invasin IpaB (IpaB)
Mol. type   Protein
Organism   Shigella flexneri
Olig. state   Monomer
Mon. MW   62.2 kDa
 
UniProt   P18011 (1-580)
Sequence   FASTA