Alpha tubulin (IPR002452)
Short name: Alpha_tubulin
Overlapping homologous superfamilies
- Tubulin/FtsZ, GTPase domain superfamily (IPR036525)
- Tubulin (IPR000217)
- Alpha tubulin (IPR002452)
Microtubules are polymers of tubulin, a dimer of two 55kDa subunits, designated alpha and beta [PMID: 3896122, PMID: 2194680]. Within the microtubule lattice, alpha-beta heterodimers associate in a head-to-tail fashion, giving rise to microtubule polarity. Fluorescent labelling studies have suggested that tubulin is oriented in microtubules with beta-tubulin toward the plus end [PMID: 8102497]. For maximal rate and extent of polymerisation into microtubules, tubulin requires GTP. Two molecules of GTP are bound at different sites, termed N and E. At the E (Exchangeable) site, GTP is hydrolysed during incorporation into the microtubule. Close to the E site is an invariant region rich in glycine residues, which is found in both chains and is thought to control access of the nucleotide to its binding site [PMID: 3680207].
Most species, excepting simple eukaryotes, express a variety of closely related alpha- and beta-isotypes. A third family member, gamma tubulin, has also been identified in a number of species [PMID: 8274140].
This entry represents alpha tubulin.
- PR01162 (ALPHATUBULIN)