________ are used to convert the chemical energy of ATP hydrolysis to mechanical motion.
Molecular motor proteins
They undergo a ____ cycle of filament binding, conformational change, and filament release.
____ are used for diverse processes from muscle contraction to vesicle movement.
Actin based motors
Microtubule based motors
Kinesins and Dyneins
Kinesin and kinesin-like proteins
Plus-end directed motors
Minus-end directed motors
The first motor characterized in detail?
Myosin II structure
- one of the most abundant proteins in the body
- other proteins associate at neck region
- long tail is composed of coiled-coiled secondary structure
Myosin II forms ____
bipolar thick filaments
- dark band = myosin II thick filaments
- light band = actin (thin filaments)
- actin binding protein, binds to (+) end of actin filament
- in Z disc of sarcomere
- binds to the (-) end of actin filament
- anchors bipolar thick filaments into Z disc
The ___ region of Myosin II is suscepltible to protease cleavage
Myosin II subdomains
How does myosin II S1 fragment work?
- myosin light chains wrap around the alphahelical segment to change position for substrate binding
The two myosin light chains are similiar in structure to ____
The myosin superfamily are...
plus-end directed actin motors
Which myosin has minus end movement?
The myosin superfamily share a ____
Kinesin and Kinesin-related proteins are...
plus-end directed microtubule motors
- best characterized of the kinesins
- globular motor domains
- forms dimers (polar structures)
-is a catastrophin (has no motor activity
-frays the (+) end of microtubule
- minus end movement
- minus end directed microtubule motors
- fastest of the motors
What are the two types of Dyneins?