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Figure S3. Photobleaching of Myo4p-GFP and Myo2p-GFP. Photobleaching analysis of Myo4p-GFP and Myo2p-GFP bound to actin in rigor reveals that the majority of Myo4p-GFP bleaches in a single step, whereas Myo2p-GFP bleaches in two steps. Two-peak Gaussian curves fit both Myo4p-GFP and Myo2p-GFP. Single-bleach steps with Myo2p likely reflect a pool of molecules with either one GFP previously bleached, or with a GFP missing due to clipping of the C-terminal tail during purification. Top, distribution of bleach step sizes, bin size is 5,000 AU. Bottom, representative spot intensity traces for Myo4p-GFP and Myo2p-GFP.