Domain structure and SDS gels of expressed Myo51. (A) Schematic of the domain structure of the Myo51 heavy chain. Residue numbers for individual domains of the heavy chain are given. The green curves represent Rng8/9 binding to the tail of Myo51 based on a previous study (Wang et al., 2014). (B) 4–20% SDS-PAGE gel showing molecular mass standards (lane 1), purified Myo51 coexpressed only with light chains Cam1 and Cdc4 (lane 2), and purified Myo51 coexpressed with light chains Cam1 and Cdc4, and Rng8 and Rng9 (lane 3). The band with an asterisk indicates a mixture of small degradation products (lane 3) identified by mass spectrometry. The dashed line (lane 3) is a small amount of bacterially expressed Cam1 that was supplemented throughout purification to facilitate light chain association. The bacterially expressed light chains migrate slower than those expressed in Sf9 cells, with no differences in primary protein sequences. (C) Predicted α-helical coiled-coil probability for the tail regions of Myo51 and vertebrate MyoVa (Paircoil2 analysis). Amino acids 893–1,471 of Myo51 and amino acids 908–1,853 of mouse MyoVa are shown. The arrow indicates the starting residue of the globular tail domain (amino acid 1,461) of MyoVa and dashed lines indicate the 0.5 probability cutoff. Myo51 is predicted to have only four heptad repeats.