Kinesin motor, catalytic domain. ATPase. Microtubule-dependent molecular motors that play important roles in intracellular transport of organelles and in cell division.

Kinesin motor domain.

Kinesin motor domain, KIFC2/KIFC3/ncd-like carboxy-terminal kinesins. Ncd is a spindle motor protein necessary for chromosome segregation in meiosis. KIFC2/KIFC3-like kinesins have been implicated in motility of the Golgi apparatus as well as dentritic and axonal transport in neurons. This catalytic (head) domain has ATPase activity and belongs to the larger group of P-loop NTPases. Kinesins are microtubule-dependent molecular motors that play important roles in intracellular transport and in cell division. In this subgroup the motor domain is found at the C-terminus (C-type). C-type kinesins are (-) end-directed motors, i.e. they transport cargo towards the (-) end of the microtubule. Kinesin motor domains hydrolyze ATP at a rate of about 80 per second, and move along the microtubule at a speed of about 6400 Angstroms per second. To achieve that, kinesin head groups work in pairs. Upon replacing ADP with ATP, a kinesin motor domain increases its affinity for microtubule binding and locks in place. Also, the neck linker binds to the motor domain, which repositions the other head domain through the coiled-coil domain close to a second tubulin dimer, about 80 Angstroms along the microtubule. Meanwhile, ATP hydrolysis takes place, and when the second head domain binds to the microtubule, the first domain again replaces ADP with ATP, triggering a conformational change that pulls the first domain forward.

This family is most closely related to the GT1 family of glycosyltransferases. The yeast gene ALG1 has been shown to function as a mannosyltransferase that catalyzes the formation of dolichol pyrophosphate (Dol-PP)-GlcNAc2Man from GDP-Man and Dol-PP-Glc-NAc2, and participates in the formation of the lipid-linked precursor oligosaccharide for N-glycosylation. In humans ALG1 has been associated with the congenital disorders of glycosylation (CDG) designated as subtype CDG-Ik.

transferase, transferring glycosyl groups