Figure 3.

Representative traces showing single-molecule actomyosin interactions in the optical trap for (A) myo1b^IQ and (B) myo1b^a. Data were collected with the use of the three-bead assay (see Materials and Methods). The number of points in the traces was reduced 30-fold for presentation. Each trace shows 50 s of data. Note the reduction in the size of the working stroke and in the attachment durations in the presence of calcium. The expanded region shows 5 s of data (without reducing the number of points) to highlight the presence of binding events in the presence of calcium.