Protein of the Week: kinesin
Kinesin (PDB code 3KIN, structure generated with PyMOL) is one of a handful of eukaryotic motor proteins. It attaches to its cargo at the end of long α-helices (we see a portion of them in the center of this ribbon diagram) and uses its ungainly feet to walk along microtubules.
A space-filling model demonstrates how large its feet are relative to its skinny helical legs.
To appreciate the full beauty of kinesin we really need to see it in action. Crystal structures of several stages of nucleotide hydrolysis and release have provided a template for animations of its walk:
To see kinesin working within the context of the cell, check out the work of the BioVisions group at Harvard.