C Far-UV CD spectra at 20°C (top) and thermal denaturation monitored at 222 nm (bottom) for Myc (red) and Max (black) bHLH-LZ constructs (at 16 μM and 8μM, respectively), alone or in combination (Myc+Max), as indicated. SUM Myc+Max: theoretical sum of the individual Myc and Max curves. The Myc variant used (WT, RA or HEA) is indicated at the top. The increased ellipticity signals at 222 nm and increased melting temperatures of the experimental Myc+Max mixtures (blue) compared to the theoretical sums (grey) demonstrate that MycWT, MycHEA and MycRA heterodimerize with Max to comparable extents. 