Tubulin | |||||||||
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kif1a head-microtubule complex structure in atp-form
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Identifiers | |||||||||
Symbol | Tubulin | ||||||||
Pfam | PF00091 | ||||||||
Pfam clan | CL0442 | ||||||||
InterPro | IPR003008 | ||||||||
PROSITE | PDOC00201 | ||||||||
SCOP | 1tub | ||||||||
SUPERFAMILY | 1tub | ||||||||
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Available protein structures: | |
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Pfam | structures |
PDB | RCSB PDB; PDBe; PDBj |
PDBsum | structure summary |
Tubulin in molecular biology can refer either to the tubulin protein superfamily of globular proteins, or one of the member proteins of that superfamily. α- and β-tubulins polymerize into microtubules, a major component of the eukaryotic cytoskeleton.Microtubules function in many essential cellular processes, including mitosis. Tubulin-binding drugs kill cancerous cells by inhibiting microtubule dynamics, which are required for DNA segregation and therefore cell division.
In eukaryotes there are six members of the tubulin superfamily, although not all are present in all species (see below). Both α and β tubulins have a mass of around 50 kDa and are thus in a similar range compared to actin with ~42 kDa. In contrast, tubulin polymers (microtubules) tend to be much bigger than actin filaments due to their cylindrical nature.
Tubulin was long thought to be specific to eukaryotes. More recently, however, several prokaryotic proteins have been shown to be related to tubulin.
Tubulin is characterized by the evolutionarily conserved Tubulin/FtsZ family, GTPase protein domain.
This GTPase protein domain is found in all eukaryotic tubulin chains, as well as the bacterial protein TubZ, the archaeal protein CetZ, and the FtsZ protein family widespread in Bacteria and Archaea.