% Helicity N One letter code for amino acids. IC50 values given as the mean value and corresponding standard deviation (SD) determined from triplicate competition FA assays against fluorescein labelled WT N-Myc61-89 FAM (50 nM) in the presence of Aurora-A 122-403 C290A/C393A (15 µM) (n = 3). All assays were performed in 25 mM Tris, 150 mM NaCl, 5 mM MgCl2, pH 7.5 and left to equilibrate for 2 h at room temperature before measuring. Mean residue ellipticity and estimated % Helicity as measured in 25 mM Tris, 150 mM NaCl, 5 mM MgCl2, pH 7.5 at 5 °C by CD spectroscopy and calculated using equations 6 and 7 (n = 2).