The switch that does not flip: the blue-light receptor YtvA from Bacillus subtilis adopts an elongated dimer conformation independent of the activation state as revealed by a combined AUC and SAXS study.

Jurk M, Dorn M, Kikhney A, Svergun D, Gärtner W, Schmieder P, J Mol Biol 2010 Oct 15;403(1):78-87 PubMed

SASDC56 – Blue light receptor YtvA, dark/inactive state

pfyP - Blue light photoreceptor
MWexperimental 47 kDa
MWexpected 58 kDa
VPorod 75 nm3
log I(s) 7.11×101 7.11×100 7.11×10-1 7.11×10-2
pfyP - Blue light photoreceptor small angle scattering data  s, nm-1
ln I(s)
pfyP - Blue light photoreceptor Guinier plot ln 7.12×101 Rg: 3.2 nm 0 (3.2 nm)-2 s2
pfyP - Blue light photoreceptor Kratky plot 1.104 0 3 sRg
pfyP - Blue light photoreceptor pair distance distribution function Rg: 3.2 nm 0 Dmax: 10.1 nm

Experimental data validation

Fits and models

log I(s)
 s, nm-1
pfyP - Blue light photoreceptor GASBOR model
log I(s)
 s, nm-1
pfyP - Blue light photoreceptor DAMMIF model
pfyP - Blue light photoreceptor DAMFILT model
log I(s)
 s, nm-1
pfyP - Blue light photoreceptor PDB model
Synchrotron SAXS data from solutions of Blue light receptor YtvA, dark/inactive state in PBS + 5 mM DTT, pH 7.4 were collected on the X33 camera on the storage ring DORIS III (Hamburg, Germany). Using a Pilatus 1M-W detector at a sample-detector distance of 2.7 m and at a wavelength of λ = 0.15 nm (s = 4π sin θ/λ, where 2θ is the scattering angle). Solute concentrations ranging between 1.7 and 11 mg/ml were measured at 20°C. Four successive 30 second frames were collected. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted and the different curves were scaled for protein concentration. 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.

pfyP - Blue light photoreceptor (YtvA)
Mol. type   Protein
Organism   Bacillus subtilis
Olig. state   Dimer
Mon. MW   29.1 kDa
UniProt   O34627 (Gly+2-261)
Sequence   FASTA
PDB code   2MWG