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
kif1a head-microtubule complex structure in atp-form
Tubulin and microtubule metrics
Comparison of the architectures of a 5-protofilament bacterial microtubule (left; BtubA in dark blue; BtubB in light-blue) and a 13-protofilament eukaryotic microtubule (right; α-tubulin in white; β-tubulin in black). Seams and start-helices are indicated in green and red, respectively.
The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell
The cytoskeleton consists of (a) microtubules, (b) microfilaments, and (c) intermediate filaments.
Actin cytoskeleton of mouse embryo fibroblasts, stained with phalloidin
Microtubules in a gel-fixated cell
Cross section diagram through the cilium, showing the "9 + 2" arrangement of microtubules