Tubulin is the major constituent of microtubules (PubMed:33633135). 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 (Probable). Dimer of alpha and beta chains (Probable). A typical microtubule is a hollow water-filled tube with an outer diameter of 25 nm and an inner diameter of 15 nM. Alpha-beta heterodimers associate head-to-tail to form protofilaments running lengthwise along the microtubule wall with the beta-tubulin subunit facing the microtubule plus end conferring a structural polarity. Microtubules usually have 13 protofilaments but different protofilament numbers can be found in some organisms and specialized cells (Probable). Interacts with DCX/apicortin; the interaction stabilizes microtubule assembly (PubMed:33633135). Localizes to the parasite surface in subpellicular regions in trophozoites and schizonts (PubMed:33633135). In merozoites, localize to the apical end of the parasite (PubMed:33633135). Expressed during the parasite blood stage, including in trophozoites, schizonts and free merozoites (at protein level). Tamoxifen used to treat breast cancer blocks the interaction between apicortin and, alpha-tubulin 1 and beta-tubulin resulting in microtubule destabilization. Belongs to the tubulin family.