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
(sRg)2I(s)/I(0)
Cold shock-like protein Kratky plot 1.104 0 √3 sRg
p(r)
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 (DESY; 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