A protein contains both an N-terminal mitochondrial matrix targeting sequence and an internal
ER start transfer sequence. Where do you think this protein goes?
The Attempt at a Solution
I've been told that it would still go to the ER. I know that when the ER start transfer sequence emerges from the ribosome, the SRP directs it to the ER membrane. Since that sequence is in the middle of the polypeptide, wouldn't the N-terminal mitochondrial matrix targeting sequence, which is right at the front, direct the protein to the receptors on the mitochondria first? Does one sequence have a stronger/higher priority than the other?