6u0h is a 2 chain structure with sequence from Tetrahymena thermophila. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
TBA_TETTH Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain.