Structural Analysis of the Microtubule–Kinesin Complex by Cryo-Electron Microscopy
The structures of microtubule-kinesin complexes have been intensely studied within the last few years by using negative stain or cryo-electron microscopy (cryo-EM; for a review, see ref. 1) and digital three-dimensional (3D) image reconstruction (2, 3, 4). On a working system, these methods constitute a straightforward approach to generate 3D data at around 20 Å resolution within a few weeks. Such maps all ow the interpretation the 3D configuration of protein domains such as the binding geometry of kinesin motor heads to tubulin protofilaments (5) or the configuration of dimeric kinesin motor domains when bound to microtubules under different nucleotide conditions (6, 7, 8). More recently, the availability of near-atomic-resolution data of the components of microtubule-kinesin complexes, namely the αβ-tubulin dimer (9) and several monomeric and dimeric kinesin motor constructs (for a review, see ref. 10), made it possible to interpret the structure of an intact microtubule (11) and the motor-tubulin interactions at near-atomic detail (8,12).
KeywordsMotor Domain Tubulin Dimer Macromolecular Assembly Helical Symmetry Liquid Ethane
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