The fast kinesin from the fungus N.crassa is able to use the energy from ATP hydrolysis in order to power conformational change that leads to the extension of microtubules. Its main function is to cause the growth of hyphae, the root-like system that allows the fungus to feed. Structurally the protein shows a similar catalytic domain to many other proteins involved in nucleotide hydrolysis, especially G proteins such as Ras, suggesting a common evolutionary origin. The kinesin is the fastest yet known able to cause movement of 0.5 micrometers per second.