Structural flexibility of RNA as molecular basis for Hfq chaperone function.

Ribeiro Ede A Jr, Beich-Frandsen M, Konarev PV, Shang W, Vecerek B, Kontaxis G, Hämmerle H, Peterlik H, Svergun DI, Bläsi U, Djinović-Carugo K, Nucleic Acids Res 40(16):8072-84 (2012) Europe PMC

SASDAH5 – Complex of Hfq with DsrA

RNA chaperone Hfq
MWexperimental 51 kDa
MWexpected 79 kDa
VPorod 210 nm3
log I(s) 5.80×101 5.80×100 5.80×10-1 5.80×10-2
RNA chaperone Hfq RNA DsrA small angle scattering data  s, nm-1
ln I(s)
RNA chaperone Hfq RNA DsrA Guinier plot ln 5.80×101 Rg: 4.3 nm 0 (4.3 nm)-2 s2
RNA chaperone Hfq RNA DsrA Kratky plot 1.104 0 3 sRg
RNA chaperone Hfq RNA DsrA pair distance distribution function Rg: 4.4 nm 0 Dmax: 14.5 nm

Data validation

Fits and models

log I(s)
 s, nm-1
RNA chaperone Hfq RNA DsrA SASREF model

Synchrotron SAXS data from solutions of Complex of Hfq with DsrA in 50 mM Tris-HCL 150 mM NaCl 1.0 mM DTT, pH 7.5 were collected on the EMBL X33 camera at the DORIS III storage ring (Hamburg, Germany) using a Pilatus 1M-W detector at a sample-detector distance of 2.7 m and at a wavelength of λ = 0.15 nm , the range of momentum transfer 0.114 < s < 6.016 nm-1 was covered (l(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). Solute concentrations ranging between 2.3 and 9.4 mg/ml were measured at 35°C. Eight successive 15 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.

RNA chaperone Hfq (Hfq)
Mol. type   Protein
Organism   Escherichia coli
Olig. state   Hexamer
Mon. MW   11.2 kDa
Sequence   FASTA
RNA DsrA (Hfq_DsrA)
Mol. type   RNA
Olig. state   Monomer
Mon. MW   12 kDa
Sequence   FASTA