CD analysis of TraMΔ. (a) TraMΔ is folded in solution. The black curve represents the average of ten individual wavelength scans. The standard deviation is displayed as a shaded area. (b) Secondary structure content of TraMΔ. The NRMSD (normalized root mean square deviation) is 0.018. (c) TraMΔ unfolding and refolding characteristics. The CD spectra are shown at 298 and 368 K and after cooling to 298 K (left panel). The temperature scan at 208 nm (up- and down-scan) is shown in the right panel.