Solution structures of DEAD-box helicase DDX3X reveal the N-terminal extension binds RNA to modulate catalysis and influence conformation

Sarah Atkinson.

SASDR95 – ATP-dependent RNA helicase DDX3X (amino acids 135-580)

ATP-dependent RNA helicase DDX3X (truncation; amino acids 135-580)
MWexperimental 50 kDa
MWexpected 52 kDa
VPorod 77 nm3
log I(s) 2.23×10-2 2.23×10-3 2.23×10-4 2.23×10-5
ATP-dependent RNA helicase DDX3X (truncation; amino acids 135-580) small angle scattering data  s, nm-1
ln I(s)
ATP-dependent RNA helicase DDX3X (truncation; amino acids 135-580) Guinier plot ln 2.23×10-2 Rg: 3.1 nm 0 (3.1 nm)-2 s2
(sRg)2I(s)/I(0)
ATP-dependent RNA helicase DDX3X (truncation; amino acids 135-580) Kratky plot 1.104 0 3 sRg
p(r)
ATP-dependent RNA helicase DDX3X (truncation; amino acids 135-580) pair distance distribution function Rg: 3.1 nm 0 Dmax: 9.2 nm

Data validation


Fits and models


log I(s)
 s, nm-1
ATP-dependent RNA helicase DDX3X (truncation; amino acids 135-580) DAMFILT model
ATP-dependent RNA helicase DDX3X (truncation; amino acids 135-580) DAMMIN model

Synchrotron SAXS data from solutions of ATP-dependent RNA helicase DDX3X (135-580) in 20 mM Tris, 150 mM NaCl, 10% (v/v) glycerol, 1 mM TCEP, pH 8 were collected on the SAXS/WAXS beam line at the Australian Synchrotron (Melbourne, Australia) using a Pilatus 1M detector at a sample-detector distance of 1.4 m and at a wavelength of λ = 0.103 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). In-line size-exclusion chromatography (SEC) SAS was employed. The SEC parameters were as follows: A 50.00 μl sample at 10 mg/ml was injected at a 0.30 ml/min flow rate onto a GE Superdex 200 5/150 column at 16°C. 51 successive 1 second frames were collected through the sample SEC elution peak. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

ATP-dependent RNA helicase DDX3X (truncation; amino acids 135-580)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Monomer
Mon. MW   51.8 kDa
 
UniProt   O00571 (135-580)
Sequence   FASTA