Figure 4.

KIF3 mantATP and mantADP titration experiments. A MT·KIF3 complex was rapidly mixed with varying concentrations of mantATP or mantADP (final concentrations of 10 μm MT, 2 μm KIF3 heterodimer, and mantATP/mantADP at 0.5, 1.5, and 5 μm). The fluorescence emission of mantATP–bound KIF3 motors was compared with that of mantADP– KIF3 motors. A, the KIF3AC family of fluorescence transients. B, the KIF3AB family of fluorescence transients. Transients corresponding to titrations of mantATP are colored, and transients corresponding to titrations of mantADP are indicated in black.