Class Notes (1,100,000)
CA (630,000)
York (40,000)
BIOL (2,000)
BIOL 2021 (200)
Lecture

BIOL 2021 Lecture Notes - Tuberculosis, Coiled Coil, Transmission Electron Microscopy


Department
Biology
Course Code
BIOL 2021
Professor
Julie Clark

This preview shows pages 1-3. to view the full 14 pages of the document.
BIOL 2021- April 288th 2009
CHAPTER 16 PART 2: MOTOR PROTEINS AND CELL MOVEMENT
MOTOR PROTEINS
- Myosin: motor head and selective head
- Myosin II:
Two heavy chains and 2 light chains
Tail= coiled coil
Found in muscles -> muscle thick fibers
Heads facing in opposite directions

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

KINESIN
- Same family as myosin
- Moves on microtubules
- 2 heavy chains and 2 light chains
- Motor domain and coiled coil tail
- On microtubules and walk to the plus end (most do)
A few go to the minus end
- Tail has a binding site that attaches;
Binds to an organelle or microtubules
- Function: carry organelles OR slide microtubules
DYNEIN

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

- Moves on microtubules
- All go to minus end
- Variable numbers of chains
- Found in vesicle trafficking and in cilia and flagella
Q- no known proteins move on intermediate filaments because of no polarity
MOTOR PROTEIN MECHANISMS
- All involve ATP binding and hydrolysis causing motor proteins to undergo large conformational
changes and changes in the affinity for the filament
Mechanical cycle
1) Filament binds to motor head
2) Cant change in motor protein
3) Releases from filament
4) Large conformational change is reversed-> relaxation of conformation
5) Filament rebinding
MYOSIN CYCLE
You're Reading a Preview

Unlock to view full version