Tubulin is the major constituent of microtubules. The gamma chain is found at microtubule organizing centers (MTOC) such as the spindle poles or the centrosome, suggesting that it is involved in the minus-end nucleation of microtubule assembly. Expressed in between seam cells at the lima-bean, 1.5-fold and 3-fold stages of embryonic development. Belongs to the tubulin family.