Inter-domain Flexibility of Chikungunya Virus nsP2 Helicase-Protease Differentially Influences Viral RNA Replication and Infectivity.

Law YS, Wang S, Tan YB, Shih O, Utt A, Goh WY, Lian BJ, Chen MW, Jeng US, Merits A, Luo D, J Virol (2020) Europe PMC

SASDK82 – Full-length nonstructural protein 2 (nsP2) of Chikungunya virus (CHIKV)

NsP2 protein
MWexperimental 90 kDa
MWexpected 90 kDa
VPorod 134 nm3
log I(s) 1.06×10-1 1.06×10-2 1.06×10-3 1.06×10-4
NsP2 protein small angle scattering data  s, nm-1
ln I(s)
NsP2 protein Guinier plot ln 1.06×10-1 Rg: 3.9 nm 0 (3.9 nm)-2 s2
(sRg)2I(s)/I(0)
NsP2 protein Kratky plot 1.104 0 √3 sRg
p(r)
NsP2 protein pair distance distribution function Rg: 3.8 nm 0 Dmax: 12 nm

Data validation

Fits and models

log I(s)
 s, nm-1
NsP2 protein CORAL model
Synchrotron SAXS data from solutions of nsP2 proteins in buffer containing 20 MM Hepes pH7.4, 150 mM NaCl, 1 mM DDT, 5% glycerol was measured at 288 K at the 23A small/wide angle X-ray scattering (SWAXS) endstation of the National Synchrotron Radiation Research Center (Hsinchu, Taiwan). First, 0.1 mL of nsP2 was injected into an HPLC system (Agilent chromatographic system 1260 series) equipped with an online size exclusion column at a flow rate of 0.035 mL/min for SAXS data collection. A 15 keV X-ray beam irradiated the sample flow within a thin-wall (30 μm) quartz capillary cell (2.0 mm diameter) for SAXS measurements (30 s/frame). The sample-to-detector distance (3.42 m) together with a Pilatus 1M-F area detector covers an X-ray momentum transfer q range of 0.01 Å-1 to 0.25 Å-1 (q = 4πλ-1sinθ, where 2θ is the scattering angle, and λ = 0.8266 Å is the wavelength of the X-rays).

NsP2 protein
Mol. type   Protein
Organism   Chikungunya virus
Olig. state   Monomer
Mon. MW   89.7 kDa
 
UniProt   F2YI08-1
Sequence   FASTA
 
PDB ID   4ZTB