Extended Data Fig. 4: NMR analysis of M1.
From: The native structure of the assembled matrix protein 1 of influenza A virus
a, 1H–15N HSQC spectrum of full-length M1 at pH 5. The spectrum is representative of three independent sample preparations. b, Representative diffusion curves acquired at pH 5 and 7, and fitted diffusion coefficients and calculated radii of hydration at pH values 5, 6, 7, 8 and 10. Error bars indicate the uncertainties of the intensities of the picked peak using Bruker Dynamics Center 2.6.1. HYDROPRO53 calculated radii of hydration are listed below for comparison. c, 1H–15N HSQC spectra of full-length M1 at different pH values. Increasing pH in absence of DNA and membrane does not induce folding of the CTD. At high pH (>8), only resonances from the first part of the NTD are visible. The protein remains largely monomeric throughout the pH titration. d, Secondary chemical shifts analysis. When compared to random coil, positive Cα and negative Cβ chemical shifts designate α-helical secondary structure. α-Helical segments from the single-particle structure are depicted above for comparison. Missing assignments are indicated by blue dots.
