Beta-tubulin; associates with alpha-tubulin (Tub1p and Tub3p) to form tubulin dimers, which polymerize to form microtubules; carboxyl-terminal tail is required for the depolymerase activity of Kip3p, a kinesin-8 motor; mutation in human ortholog is associated with congenital fibrosis of the extraocular muscles (CFEOM) with polymicrogyria