Analytical ultracentrifugation studies of FLASH NTD, FLASH NTD mutants, Lsm11, and FLASH NTD-Lsm11 NTD complex.

<p>(A) Typical traces of absorbance at 280 nm of the protein in 20 mM Tris (pH 7.5) buffer during the sedimentation velocity experiment. The protein concentration was 1 mg/ml. For clarity, only every fifth scan is shown. The symbols represent experimental data and the lines are the results obtained after being fitted to the Lamm equation using the SEDFIT program [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0186034#pone.0186034.ref057" target="_blank">57</a>]. (B-E) Continuous c(s) distribution of FLASH NTD wild-type, C54S/C83A mutant, FLASH NTD-Lsm11 NTD complex and Lsm11 NTD. The distributions of the proteins at concentrations of 1 mg/ml (B-D) and 0.8 mg/ml (E) are shown by solid lines and those at concentrations of 0.1 mg/ml (B) and 0.05 mg/ml (D) are shown by dashed lines and that at 8 mg/ml (D) are showed by dotted line. The y-axis on the right is for the protein at a concentration of 0.1 mg/ml (B) and 8 mg/ml (D). The vertical dashed lines on the left and right indicate the monomer position of Lsm11 NTD and the dimer position of FLASH NTD, respectively. The residual bitmap of the raw data and the best-fit results are shown in the insets. The data are summarized in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0186034#pone.0186034.t002" target="_blank">Table 2</a>.