Decoupling of size and shape fluctuations in heteropolymeric sequences reconciles discrepancies in SAXS vs. FRET measurements.

Fuertes G, Banterle N, Ruff KM, Chowdhury A, Mercadante D, Koehler C, Kachala M, Estrada Girona G, Milles S, Mishra A, Onck PR, Gräter F, Esteban-Martín S, Pappu RV, Svergun DI, Lemke EA, Proc Natl Acad Sci U S A 114(31):E6342-E6351 (2017) Europe PMC

SASDE73 – Unlabeled cold shock protein (CSP) with denaturant

Cold shock-like protein
MWexperimental 11 kDa
MWexpected 7 kDa
VPorod 17 nm3
log I(s) 2.83×102 2.83×101 2.83×100 2.83×10-1
Cold shock-like protein small angle scattering data  s, nm-1
ln I(s)
Cold shock-like protein Guinier plot ln 2.84×102 Rg: 2.5 nm 0 (2.5 nm)-2 s2
Cold shock-like protein Kratky plot 1.104 0 3 sRg
Cold shock-like protein pair distance distribution function Rg: 2.7 nm 0 Dmax: 11.5 nm

Data validation

There are no models related to this curve.

Synchrotron SAXS data from solutions of Unlabeled cold shock protein (CSP) with denaturant in PBS, 10 mM DTT, 6 M urea, 0.3 M KCl, pH 7.4 were collected on the EMBL P12 beam line at the PETRA III storage ring (Hamburg, Germany) using a Pilatus 2M detector at a sample-detector distance of 3 m and at a wavelength of λ = 0.1 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 10.00 mg/ml was measured at 23°C. 20 successive 0.050 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.

The protein contains a penultimate non-canonical amino acid p-acetylphenylalanine (207 Da) that is represented as U (selenocysteine, 168 Da) in the amino acid sequence for the entry. Therefore, the calculated MW from sequence (MW(expected)) must be adjusted accordingly (ca. 40 Da).

Tags: idp
Cold shock-like protein (CSP)
Mol. type   Protein
Organism   Thermotoga maritima
Olig. state   Monomer
Mon. MW   6.6 kDa
UniProt   O54310 (3-58)
Sequence   FASTA