Fig. 1

Biochemical analyses of the interaction between Myosin VI and Tom1. a A schematic diagram showing the domain arrangements of Myosin VI, Tom1, NDP52, TAX1BP1, and Optineurin. In this drawing, domains involved in the protein–protein interaction are highlighted with black lines, and the relevant interactions between two proteins are indicated by two-way arrows. b Superposition plots of the ¹H-¹⁵N HSQC spectra of Tom1(392–463) titrated with the un-labeled C-terminal CBD of Myosin VI proteins at different molar ratios. For clarity, the insert shows the enlarged view of a unique peak corresponding to the side chain of Tom1 W423 residue in the overlaid ¹H-¹⁵N HSQC spectra. c–e ITC-based measurements of the binding affinities of the C-terminal CBD of Myosin VI with Tom1(392–463) (c), Tom1(392–437) (d), and Tom1(437–463) (e). Kd values are the fitted dissociation constants with standard errors, when using the one-site binding model to fit the ITC data. ‘N.D.’ stands for that the Kd value is not detectable. Source data are provided as a Source Data file. f Overlay plots of the multi-angle light-scattering data of the C-terminal CBD of Myosin VI, Tom1(437–463), and the C-terminal CBD of Myosin VI in complex with Tom1(437–463). The derived molecular masses of the C-terminal CBD of Myosin VI and Tom1(437–463) are shown in red and in blue, respectively, while the derived molecular mass of the C-terminal CBD of Myosin VI and Tom1(437–463) complex is shown in black. The molecular masses errors are the fitted errors obtained from the data analysis software, and are showed in the brackets. The results clearly demonstrate that the C-terminal CBD of Myosin VI and Tom1(437–463) both form a stable monomer and may interact with each other to form a 1:1 stoichiometric complex in solution. Source data are provided as a Source Data file