Motor proteins

thumb|Part of the myosin II structure. Atoms in the heavy chain are colored pink (on the left-hand side); atoms in the light chains are colored faded-orange and faded-yellow (also on the left-hand side). Myosins () are a family of motor proteins (though most often protein complexes) best known for their roles in muscle contraction and in a wide range of other motility processes in eukaryotes. They are ATP-dependent and responsible for actin-based motility.

thumb|The kinesin dimer (red) attaches to, and moves along, microtubules (blue and green). thumb|Animation of kinesin "walking" on a [[microtubule. Protein domain dynamics can only now be seen by neutron spin echo spectroscopy.]] A kinesin is a protein complex belonging to a class of motor proteins found in eukaryotic cells. Kinesins move along microtubule (MT) filaments and are powered by the hydrolysis of adenosine triphosphate (ATP) (thus kinesins are ATPases, a type of enzyme). The active movement of kinesins supports several cellular functions including mitosis, meiosis and transport of c

thumbnail|right|Cytoplasmic dynein on a microtubule Dyneins are a family of cytoskeletal motor proteins (though they are actually protein complexes) that move along microfilaments in cells. They convert the chemical energy stored in ATP to mechanical work. Dynein transports various cellular cargos, provides forces and displacements important in mitosis, and drives the beat of eukaryotic cilia and flagella. All of these functions rely on dynein's ability to move towards the minus-end of the microtubules, known as retrograde transport; thus, they are called "minus-end directed motors". In contra

class of molecular motors

thumb|400px|Quaternary structure of dynactin Dynactin is a 23 subunit protein complex that acts as a co-factor for the microtubule motor cytoplasmic dynein-1. It is built around a short filament of actin related protein-1 (Arp1).

Myosin-7 is a protein that in humans is encoded by the MYH7 gene.

Kinesin-like protein KIF1A, also known as axonal transporter of synaptic vesicles or microtubule-based motor KIF1A, is a protein that in humans is encoded by the KIF1A gene.

Kinesin family member KIF18A is a human protein encoded by the KIF18A gene. It is part of the kinesin family of motor proteins.

Kinesin-like protein KIF2A is a protein that in humans is encoded by the KIF2A gene. In mice, KIF2A is essential for proper neurogenesis and deficiency of KIF2A in mature neurons results in the loss of those neurons.

Kinesin-like protein KIF3C is a protein that in humans is encoded by the KIF3C gene. It is part of the kinesin family of motor proteins.

Kinesin-like protein KIF1C is a protein that in humans is encoded by the KIF1C gene. Kif1C is a fast, plus-end directed microtubule motor. It takes processive 8nm steps along microtubules and can generate forces of up to 5 pN. Kif1C transports α5β1-integrins in human cells. Kif1C has been shown to be non-essential in mouse with other proteins able to perform the same function. However, mutations in KIF1C lead to spastic paraplegia and cerebellar dysfunction in humans. These mutations usually result in a total loss of the protein or (partial) loss of function, such as significant lower force ou

Kinesin family member 5B (KIF5B) is a protein that in humans is encoded by the KIF5B gene. It is part of the kinesin family of motor proteins.