Final answer:
Kinesin motors are ATPase proteins that move cargo along microtubule tracks towards the plus end of the microtubule. They are dimeric, with motor domains for microtubule binding and light chains for cargo binding. These motor proteins are crucial for anterograde transport in cells.
Step-by-step explanation:
Kinesin motors are a class of motor proteins that play a critical role in intracellular transport. They are ATPases, using the energy from ATP hydrolysis to move cargo along microtubule tracks within cells.
Kinesin motors typically have two heavy chains that form a coiled-coil tail and two light chains that associate with cargo molecules, such as organelles or vesicles. The heavy chains also contain a motor domain that binds to and 'walks' along microtubules. The light chains are involved in cargo binding, with different kinesins binding to different types of cargo.
Kinesin moves in an anterograde fashion, meaning it typically carries cargo from the center of the cell towards the periphery. This is in contrast to dynein, another motor protein, which moves cargo in the retrograde direction, from the cell periphery toward the center.
Kinesins bind to microtubules via their globular heads, which hydrolyze ATP to fuel their movement. This movement is directional, with the majority of kinesins moving towards the plus end of microtubules.
Regarding their molecular structure, kinesins form dimers with two globular heads that interact with microtubules. These heads undergo conformational changes during the ATP hydrolysis cycle that allow for the hand-over-hand movement along the microtubule tracks. The dimeric nature of kinesins is essential for their function, as it contributes to their processivity, which is their ability to take multiple steps along a microtubule without detaching.