Biophysical characterization of cementoin. A) CD spectra of cementoin with varying concentrations of TFE (up to 75%). The vertical lines indicate 208 and 222 nm, i.e. characteristic wavelengths for assessing the presence of α-helices. B) 2 D 15N-HSQC spectrum of cementoin in the presence of 50% TFE. Backbone assignments are shown. Side-chain Asn, Gln and Arg doublets are depicted with a line between the two resonances while unassigned additional peaks (potentially arising from slow exchange, see text) are labeled by an asterisk (*). C) SSP analysis of backbone Cα and Cβ chemical shifts. Secondary structure predictions depend on the result where positive values infer α-helices and negative values, β-sheets. D) Secondary structure predictions from AGADIR with α-helices shown as black boxes.