Figure 1.
Biological motors. (a) Cytoskeleton motors move along a one-dimensional filament of actins or tubulins. Shown is a kinesin carrying a vesicle cargo along a microtubule track. (b) Rotary motors couple biochemical reactions to rotary motion. For example, F0F1-ATP synthase converts a proton gradient across a membrane into the chemical energy by synthesizing ATP or vice versa. (c) Various motors, including DNA/RNA polymerase, helicase, and ribosome, move along nucleic acids to polymerize biopolymers or to change their geometric conformations. A helicase which unwinds double stranded DNA or RNA into single strands is shown.