The core of the motor domain determines the direction of myosin movement

• Published in: Nature (London) Vol. 412; no. 6849; pp. 831 - 834
• Main Authors: Ikebe, Mitsuo, Homma, Kazuaki, Yoshimura, Misako, Saito, Junya, Ikebe, Reiko
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 23.08.2001; Nature Publishing Group
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Calmodulin - genetics; Cell Line; Cells; Contractile proteins; Fundamental and applied biological sciences. Psychology; Holoproteins; Mice; Molecular biology; Molecular Motor Proteins - chemistry; Molecular Motor Proteins - physiology; Molecules; Movement; Myosins - chemistry; Myosins - genetics; Myosins - physiology; Protein Structure, Tertiary; Proteins; Rabbits; Recombinant Fusion Proteins; Structure-Activity Relationship; Xenopus; Contractile protein; Microfilament; Motility; Actin; Molecular domain; Myosin
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/35090597

Myosins constitute a superfamily of at least 18 known classes of molecular motors that move along actin filaments. Myosins move towards the plus end of F-actin filaments; however, it was shown recently that a certain class of myosin, class VI myosin, moves towards the opposite end of F-actin, that is, in the minus direction. As there is a large, unique insertion in the myosin VI head domain between the motor domain and the light-chain-binding domain (the lever arm), it was thought that this insertion alters the angle of the lever-arm switch movement, thereby changing the direction of motility. Here we determine the direction of motility of chimaeric myosins that comprise the motor domain and the lever-arm domain (containing an insert) from myosins that have movement in the opposite direction. The results show that the motor core domain, but neither the large insert nor the converter domain, determines the direction of myosin motility.