Download MendeleyThe beginning of kinesin's force-generating cycle visualized at 9-A resolution.
Sindelar, C.V., Downing, K.H.(2007) J Cell Biol 177: 377-385
- PubMed: 17470637
- DOI: https://doi.org/10.1083/jcb.200612090
- Primary Citation of Related Structures:
2P4N - PubMed Abstract:
We have used cryo-electron microscopy of kinesin-decorated microtubules to resolve the structure of the motor protein kinesin's crucial nucleotide response elements, switch I and the switch II helix, in kinesin's poorly understood nucleotide-free state. Both of the switch elements undergo conformational change relative to the microtubule-free state. The changes in switch I suggest a role for it in "ejecting" adenosine diphosphate when kinesin initially binds to the microtubule. The switch II helix has an N-terminal extension, apparently stabilized by conserved microtubule contacts, implying a microtubule activation mechanism that could convey the state of the bound nucleotide to kinesin's putative force-delivering element (the "neck linker"). In deriving this structure, we have adapted an image-processing technique, single-particle reconstruction, for analyzing decorated microtubules. The resulting reconstruction visualizes the asymmetric seam present in native, 13-protofilament microtubules, and this method will provide an avenue to higher-resolution characterization of a variety of microtubule- binding proteins, as well as the microtubule itself.
Organizational Affiliation:
Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
