Which of the Following Statements is Not True of Proteins

Question

Which of the following statements is not true of proteins destined for the ER?
A)They have a signal sequence.
B)The signal sequence for the ER consists of 15-30 amino acids.
C)The proteins are modified with carbohydrates in the ER.
D)The signal sequence is subsequently removed from the mature protein.
E)The SRP binds to the protein and prevents entry into the ER until translation is completed.

Accepted Answer

The SRP (signal recognition particle) actually binds to the protein and targets it to the ER for entry during translation. It does not prevent entry until translation is completed. Therefore, statement E is not true.