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推薦原始出處：
Cell, Volume 138, Issue 3, 537-548, 7 August 2009 doi:10.1016/j.cell.2009.05.030
Myosin VI Undergoes Cargo-Mediated Dimerization
Cong Yu1,3,Wei Feng1,3,Zhiyi Wei1,Yohei Miyanoiri1,Wenyu Wen1,Yanxiang Zhao2andMingjie Zhang1,,
1 Department of Biochemistry, Molecular Neuroscience Center, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
2 Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
Myosin VI is the only known molecular motor that moves toward the minus ends of actin filaments; thus, it plays unique roles in diverse cellular processes. The processive walking of myosin VI on actin filaments requires dimerization of the motor, but the protein can also function as a nonprocessive monomer. The molecular mechanism governing the monomer-dimer conversion is not clear. We report the high-resolution NMR structure of the cargo-free myosin VI cargo-binding domain (CBD) and show that it is a stable monomer in solution. The myosin VI CBD binds to a fragment of the clathrin-coated vesicle adaptor Dab2 with a high affinity, and the X-ray structure of the myosin VI CBD in complex with Dab2 reveals that the motor undergoes a cargo-binding-mediated dimerization. The cargo-binding-induced dimerization may representa general paradigm for the regulation of processivity for myosin VI as well as other myosins, including myosin VII and myosin X.