The 15N spin relaxation profiles of MAGI1 WW2 355–390 (black), MAGI1 WW2 355–401 (red), and MAGI1 WW2 355–390 D370S (green). The heteronuclear NOE (top), longitudinal (R1; middle), and transverse (R2; bottom) relaxation profiles are shown with error bars. (Cyan arrows) β-strands, (red bar) the α-helix of the longer construct, MAGI1 WW2 355–401.