Kinesins motor domains

Hirose, K, Lockhart, A., Cross, R., and Amos, L., 1995. Nncleodde-depen-dent angnlar change in kinesin motor domain bound to tnbnlin. Nature 376 277-279. 

Knll, F. J., Sablin, E. P, Lan, R., et al., 1996. Crystal structure of die kinesin motor domain reveals a structural similarity to myosin. Nature 380 550-555. 

Fig. 19-4).212b However, single kinesin heads, which lack the coiled-coil neck region, have a duty ratio of <0.45. The movement is nonpro-cessive.213 The Ned motor is also nonprocessive.214-216 As mentioned previously, the Ned and kinesin motor domains are at opposite ends of the peptide chain, and the motors move in opposite directions along microtubules.217 218 The critical difference between the two motor molecules was found in the neck domains, which gave rise to differing symmetries in the two heads.219 The latter are shown in Fig. 19-20, in which they have been docked onto the tubulin protofilament structure.

Hirose, K., Fan, J., and Amos, L. A. (1995a). Re-examination of the polarity of microtubules and sheets decorated with kinesin motor domain. J. Mol. Biol. 251, 329-333. 

Microtubules are the intracellular tracks for two classes of motor proteins kinesins and dyneins. During the past few years, the motor domain structures of several kinesins from different organisms have been determined by X-ray crystallography. Compared with kinesins, dyneins are much larger proteins and attempts to crystallize them have failed so far. Structural information about these proteins comes mosdy from electron microscopy. In this chapter, we mainly focus on the crystal structures of kinesin motor domains. 

The first structure of a kinesin motor domain—that of human kinesin-l (formerly named KHC or conventional kinesin )—was determined by Kull and coworkers (1996). This is still the structure of highest resolution (1.8 A PDB code 1BG2) among all structures of conventional kinesins... 

Structural elements that interact with the microtubule surface have been identified by the effect of point mutations (Woehlke et al, 1997) and by fitting crystal structures of kinesin motor domains to low-resolution electron density maps obtained by cryo-electron microscopy of microtubules... 

Structural Alignment of the Switch-1 and Switch-2 Regions of Kinesin Motor Domains with Secondary Structure Assignments and Classification of the Switch-2 Cluster and Neck/Neck Linker Conformations... 

Asenjo, A. B., Krohn, N., and Sosa, H. (2003). Configuration of the two kinesin motor domains during ATP hydrolysis. Nat. Struct. Biol. 10, 836-842. 

Hirose K, Lockhart A, Cross RA, Amos LA. 1995. Nucleotide-dependent angular change in kinesin motor domain bound to tubulin. Nature 376 277. 

FIGURE 1 Surface-adhered kinesin motors can propel fluorescently labeled microtubules (diameter 25 mn) across a surface. A coating of casein proteins on the surface prevents the kinesin motor domains from attaching to the surface. The experiment is conducted in a cell composed of a cover slip, spacers, and a slide. When microtubule motion is observed with a fluorescence microscope, microtubules appear as fluorescent rods, and the kinesin motors on the surface are invisible. 

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