Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

The Nanoscale Motors of Living Systems

Movement is a fundamental property of biological organisms. The contraction of muscle, beating of cilia and flagella, segregation of genetic material during mitosis, and intracellular transport of membranes, proteins and mRNAs are all driven by protein machines that convert a chemical energy source (adenosine triphosphate) into unidirectional motion along a biological polymer (microtubules or actin filaments). These nanoscale (10-50 nm) biological machines are more efficient than most man-made machines (50-99% work efficiency). We have studied kinesin and dynein, the two different types of motors that move along microtubule tracks. To under understand the mechanisms of these motor proteins, we have solved their structures by X-ray crystallography and electron microscopy, and have investigated their stepping behavior and force production by single molecule optical techniques. Taken together, these results have yielded detailed models of how proteins produce motion and also how cells turn these motors on and off, depending upon their needs. I also will briefly talk about, our web-based science and education outreach project which is funded jointly by NIH and NSF.


vladimir.aksyuk [at] (Vladimir Aksyuk), 301-975-2867

Ronald Vale, Ph.D.

Department of Cellular and Molecular Pharmacology, University of California, San Francisco
Howard Hughes Medical Institute

Created January 14, 2015, Updated May 13, 2016