Microtubule Interaction Site of the Kinesin Motor

• Published in: Cell 1997-07, Vol.90 (2), p.207-216
• Main Authors: Woehlke, Günther, Ruby, Aaron K, Hart, Cynthia L, Ly, Bernice, Hom-Booher, Nora, Vale, Ronald D
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphatases - metabolism; Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; Escherichia coli - genetics; Kinesin - chemistry; Kinesin - genetics; Kinesin - metabolism; Microtubules - chemistry; Microtubules - enzymology; Mutagenesis, Site-Directed - physiology; Protein Binding - physiology; Protein Structure, Tertiary
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/S0092-8674(00)80329-3

Kinesin and myosin are motor proteins that share a common structural core and bind to microtubules and actin filaments, respectively. While the actomyosin interface has been well studied, the location of the microtubule-binding site on kinesin has not been identified. Using alanine-scanning mutagenesis, we have found that microtubule-interacting kinesin residues are located in three loops that cluster in a patch on the motor surface. The critical residues are primarily positively charged, which is consistent with a primarily electrostatic interaction with the negatively charged tubulin molecule. The core of the microtubule-binding interface resides in a highly conserved loop and helix (L12/α5) that corresponds topologically to the major actin-binding domain of myosin. Thus, kinesin and myosin have developed distinct polymer-binding domains in a similar region with respect to their common catalytic cores.