ABSTRACT
This chapter provides an overview of the complexity of biomolecular motors and the cellular cytoskeleton components, actin microfilaments and microtubules. Cellular molecular motors are present in a range of shapes, sizes, and capabilities dependent on the mechanistic need and can be considered as primarily chemical, nucleic acid, or protein-based in nature. The cytoskeleton motor protein toolbox in each cell varies among species. In eukaryotes, kinesin and myosin are multi-family motor proteins and appear to be ubiquitous. Dynein, however, is not universal, which suggests that cells have found a way to replace its functional roles. The location of the motor domain within the polypeptide has been found to correlate closely with directionality, that is, N-terminal for plus-end-directed motor proteins or C-terminal as in the case of kinesin-14 Klps. The development of chemical motor mechanisms remains rather primitive in terms of efficacy, control, and applications; nonetheless, it is expected to provide important contributions to nanorobotics.
