Biased binding of single molecules and continuous movement of multiple molecules of truncated single-headed kinesin.
Conventional kinesin has a double-headed structure consisting of two motor domains and moves processively along a microtubule using the two heads cooperatively. The movement of single and multiple truncated heads of Drosophila kinesin was measured using a laser trap and nanometer detecting apparatus. Single molecules of single-headed kinesin bound to the microtubules with a 3.5 nm biased displacement toward the plus end of the microtubule. The position of these single-headed kinesin molecules bound to a microtubule did not change until they had dissociated, indicating that single kinesin heads utilize nonprocessive movement processes. Two molecules of single-headed kinesin moved continuously along a microtubule with a lower velocity and force than that of single molecules of double-headed kinesin. The biased binding of the heads determines the directionality of movement, whereas two molecules of single-headed kinesin move continuously without dissociation from a microtubule.
Kamei
Takashi
T
Department of Metallurgy, School of Engineering, Tohoku University, Sendai 980-8579, Japan.
Kakuta
Seiji
S
Higuchi
Hideo
H
D000818:Animals; D001665:Binding Sites; D003198:Computer Simulation; D004330:Drosophila / Q000201:enzymology*; D016547:Kinesins / Q000032:analysis / Q000737:chemistry*; D008870:Microtubules / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry*; D009038:Motion; D011485:Protein Binding; D013314:Stress, Mechanical; D013329:Structure-Activity Relationship; D013552:Swine
D020409:Molecular Motor Proteins; D016547:Kinesins