Structural analysis of the SRP Alu domain from Plasmodium falciparum reveals a non-canonical open conformation.

Soni K, Kempf G, Manalastas-Cantos K, Hendricks A, Flemming D, Guizetti J, Simon B, Frischknecht F, Svergun DI, Wild K, Sinning I, Commun Biol 4(1):600 (2021) Europe PMC

SASDK24 – Signal recognition particle SRP9/14 heterodimer from Plasmodium falciparum

Signal recognition particle 9
Signal recognition particle 14
MWexperimental 24 kDa
MWexpected 24 kDa
VPorod 47 nm3
log I(s) 2.18×101 2.18×100 2.18×10-1 2.18×10-2
Signal recognition particle 9 Signal recognition particle 14 small angle scattering data  s, nm-1
ln I(s)
Signal recognition particle 9 Signal recognition particle 14 Guinier plot ln 2.19×101 Rg: 2.1 nm 0 (2.1 nm)-2 s2
(sRg)2I(s)/I(0)
Signal recognition particle 9 Signal recognition particle 14 Kratky plot 1.104 0 √3 sRg
p(r)
Signal recognition particle 9 Signal recognition particle 14 pair distance distribution function Rg: 2.1 nm 0 Dmax: 7.2 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Signal recognition particle 9 Signal recognition particle 14 DAMMIN model
Synchrotron SAXS data from solutions of the SRP9/14 heterodimer in 20 mM HEPES pH 7.5, 150 mM NaCl, 10 mM MgCl2, 10 mM KCl, 1mM DTT, pH 7.5 were collected on the BM29 beam line at the ESRF (Grenoble, France) using a Pilatus 1M detector at a wavelength of λ = 0.099 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 2.50 mg/ml was measured at 20°C. 10 successive 0.500 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.

Sample detector distance = UNKNOWN

Signal recognition particle 9 (SRP9)
Mol. type   Protein
Organism   Plasmodium falciparum
Olig. state   Monomer
Mon. MW   12.1 kDa
 
UniProt   F2X1X5 (1-103)
Sequence   FASTA
 
Signal recognition particle 14 (SRP14)
Mol. type   Protein
Organism   Plasmodium falciparum
Olig. state   Monomer
Mon. MW   12.0 kDa
 
UniProt   F2X1X6 (1-104)
Sequence   FASTA