molecular machine

Bacterial flagellar motor assembly: Shown here is the C-ring at the base with FliG in red, FliM in yellow, and FliN in shades of purple; the MS-ring in blue; the MotAB in brown; the LP-ring in pink; and the rod in gray.

Molecular machines are a class of molecules typically described as an assembly of a discrete number of molecular components intended to produce mechanical movements in response to specific stimuli, mimicking macromolecular devices such as switches and motors. Naturally occurring or biological molecular machines are responsible for vital living processes such as DNA replication and ATP synthesis. Kinesins and ribosomes are examples of molecular machines, and they often take the form of multi-protein complexes. Multiple examples of molecular machinery and their components are found in the Protein Data Bank. For the last several decades, scientists have attempted, with varying degrees of success, to miniaturize machines found in the macroscopic world.