Transporters

Question 1

Does ligand binding stabilise the dynamic flux of transporters?

Answer 1

No

Question 2

What discovery allowed lactose permease to be crystallised?

Answer 2

A lac permease mutant (C154G)

Question 3

Why was the C154G lactose permease mutant a useful discovery?

Answer 3

• It lacked the inward-facing conformation
• Had a higher thermal stability
• More robust
• Lacks extensive conformational dynamics of WT
• Binds sugar but does not transport it

Question 4

What was Lac permease crystallised in the presence of?

Answer 4

TDG

Question 5

Where is the ligand binding site in lac permease?

Answer 5

At the centre of the membrane

Question 6

How was the alternating access model of transporters generated?

Answer 6

The combination of experimental structures and computational modelling

Question 7

Which residues for hydrogen bonds with lactose permease?

Answer 7

• Arg144
• Lys358