October 31, 2014

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Fig. 1 Superposition of the 20 best structures of the MTBD of flagellar dynein and the nomenclatures of secondary structure elements with rainbow colors from the N- to C-termini (blue to red)(left). Mean structure viewed from the opposite side (Right). The panels were depicted with Pymol (Schrödinger, LLC., New York, NY).
Fig. 2 Surface representation with calculated electrostatic charges of MTBDs of flagellar dynein (left) and cytoplasmic dynein (right). The panels were depicted with Swiss PDB viewer (Guex and Peitsch, 1997).
© 2014 Yusuke Kato, Masaru Tanokurae

Yusuke Kato, Masaru Tanokura (Department of Applied Biological Chemistry, the University of Tokyo), Stan Burgess (Astbury Centre for Structural Molecular Biology, University of Leeds) and others have revealed the atomic structure of the microtubule-binding domain (MTBD) of the eukaryotic flagellar motor protein, flagellar dynein. Flagellar dyneins move on flagellar microtubules to drive the beating motions of cilia and flagella, and operate within the confines of the microtubular array of the axoneme. Dysfunction in flagellar dyneins associates with diverse medical conditions including male infertility and mirrored internal organ localization. The present studies have revealed the novel flexible flap structure that has been unseen in the structure of cytoplasmic dynein.

Even surprisingly, the surface charge distribution of the MTBD of flagellar dynein also differs from that of cytoplasmic dynein. These together suggest the difference in the mechanisms of microtubule-binding between those dyneins. Such different properties of flagellar dynein may be important to work together with other numerous dynein molecules in the confinement of an axoneme. The results obtained in the present studies are important for elucidating the detailed mechanism of the flagellar beating.

Paper Information

Yusuke S. Kato, Toshiki Yagi, Sarah A. Harris, Shin-ya Ohki, Kei Yura, Youské Shimizu, Shinya Honda, Ritsu Kamiya, Stan A. Burgess, and Masaru Tanokura, “Structure of the microtubule-binding domain of flagellar dynein,” Structure Online Edition: 2014/Oct/24 (Japan time), doi: http://dx.doi.org/10.1016/j.str.2014.08.021.