| First Author | Okada Y | Year | 2003 |
| Journal | Nature | Volume | 424 |
| Issue | 6948 | Pages | 574-7 |
| PubMed ID | 12891363 | Mgi Jnum | J:359814 |
| Mgi Id | MGI:7790565 | Doi | 10.1038/nature01804 |
| Citation | Okada Y, et al. (2003) Processivity of the single-headed kinesin KIF1A through biased binding to tubulin. Nature 424(6948):574-7 |
| abstractText | Conventional isoforms of the motor protein kinesin behave functionally not as 'single molecules' but as 'two molecules' paired. This dimeric structure poses a barrier to solving its mechanism. To overcome this problem, we used an unconventional kinesin KIF1A (refs 5, 6) as a model molecule. KIF1A moves processively as an independent monomer, and can also work synergistically as a functional dimer. Here we show, by measuring its movement with an optical trapping system, that a single ATP hydrolysis triggers a single stepping movement of a single KIF1A monomer. The step size is distributed stochastically around multiples of 8 nm with a gaussian-like envelope and a standard deviation of 15 nm. On average, the step is directional to the microtubule's plus-end against a load force of up to 0.15 pN. As the source for this directional movement, we show that KIF1A moves to the microtubule's plus-end by approximately 3 nm on average on binding to the microtubule, presumably by preferential binding to tubulin on the plus-end side. We propose a simple physical formulation to explain the movement of KIF1A. |
