Plasmodium falciparum Kelch13 and its artemisinin-resistant mutants assemble as hexamers in solution: a SAXS data driven modeling study.

Goel N, Dhiman K, Kalidas N, Mukhopadhyay A, Ashish F, Bhattacharjee S, FEBS J (2022) Europe PMC

SASDN85 – Truncated Kelch13-Wild Type

Kelch protein K13
MWI(0) 367 kDa
MWexpected 396 kDa
VPorod 1630 nm3
log I(s) 5.77×104 5.77×103 5.77×102 5.77×101
Kelch protein K13 small angle scattering data  s, nm-1
ln I(s)
Kelch protein K13 Guinier plot ln 5.77×104 Rg: 6.4 nm 0 (6.4 nm)-2 s2
(sRg)2I(s)/I(0)
Kelch protein K13 Kratky plot 1.104 0 √3 sRg
p(r)
Kelch protein K13 pair distance distribution function Rg: 6.6 nm 0 Dmax: 17 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Kelch protein K13 ITASSER model
log I(s)
 s, nm-1
Kelch protein K13 GASBOR model
SAXS data from solutions of truncated Kelch13 in phosphate buffered saline, pH 7.4 were collected using an Anton Paar SAXSpace at the CSIR Institute of Microbial Technology (IMTech; Chandigarh, India) equipped with a Mythen 1K detector at a wavelength of λ = 0.15441 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 1.10 mg/ml was measured at 10°C. One 3600 second frame was collected. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

CAUTION: Guinier region poorly defined. CAUTION: High variance data with poorly specified errors. CAUTION: Error estimates are recorded as negative throughout the dataset. CAUTION: Molecular weight estimates are highly variable, in the range of 260-510 kDa. CAUTION: Data are missing from the fit of the atomistic model (top) to the data.

Kelch protein K13 (TrK13-WT)
Mol. type   Protein
Organism   Plasmodium falciparum (isolate 3D7)
Olig. state   Hexamer
Mon. MW   66.1 kDa
 
UniProt   Q8IDQ2 (189-726)
Sequence   FASTA