θ_P versus ϕ_P distributions for myoV-6IQ and myoV-4IQ. (A) θ_P versus ϕ_P distributions calculated from individual processive runs of myoV-6IQ (left; n = 73 molecules) and myoV-4IQ (right; n = 49 molecules) describing the orientation of the probe in the lever frame of reference. One-dimensional histograms of θ_P and ϕ_P are displayed to the left and below them. (B) Representative traces of β_L and α_L, the orientation of the lever arm in the actin reference frame, calculated from the β_P and α_P traces shown in Fig. 3 along with the corresponding values for θ_P and ϕ_P in those molecules (6IQ: θ_P = 62° and ϕ_P = −65°; 4IQ: θ_P = 42° and ϕ_P = −124°).