E2 Catalyzes Rxn 3

Question 1

E2 lipoyl arm

Answer 1

Either end of this arm will move in to either end of E1’s active site to remove the acetyl group

Question 2

Peripheral subunit binding domain

Answer 2

The domains that are connecting the core to the outside.
Each spot is occurring about 50 A from the active sites.
These also have pivots.

Question 3

how many lipoyl domains do we have?

Answer 3

we have 2 domains

Question 4

flexible linkers

Answer 4

contain proline and alanine.
MUST REMEMBER THESE!!!!
The side chains of these amino acids allow for flexibility.
Lipoyl domains stick out from the E2 core, these interact with E1 to pick up hydroxyethy group to form acetyl-lipoamide. Then interact with E3 so that they can be regenerated (they being lipoyl domains). When regenerated, can then do what???

Question 5

Identify where the parts are in the diagram

Question 6

Pivot

Answer 6

E2’s N terminal bridge allows for mvoement between active sites

Question 7

Linker

Answer 7

Inner linker (linker) and outer linker (chain)

Question 8

link interaction

Answer 8

1. E2 lipoamide arm picks up the acetyl group form E1 TPP. (sticks head into the active site (DOES NOT ENTER PROTON WIRE) to pull out the hydroxyethyl group now attached to it as an acetyl group to the ball (lipoyl domain)
2. The pivot dissociates (dont care how) , moves to the other pivot point, which is E3, delivers the acetyl group to the CoA of E2 catalytic domain.