Arrange the events listed below in order according to the signal hypothesis:
I. Signal sequence binds to SRP
II. Translation stops
III. Translation starts
IV. Ribophorins anchor complex
V. SRP dissociates;GTP hydrolyzed
VI. SRP-signal complex binds to docking protein
A)I → II → II → IV → V → VI
B)I → III → VI → V → II → IV
C)V → III → IV → VI → II → I
D)I → II → VI → IV → III → V

Question

Quizplus · Accepted Answer

The first event in the signal hypothesis is the binding of the signal sequence to SRP (I). Then, translation starts (III), followed by the binding of the SRP-signal complex to the docking protein (VI). Ribophorins anchor the complex (IV), and then translation stops (II) to allow translocation into the ER. Finally, SRP dissociates and GTP is hydrolyzed (V). Therefore, the correct order is I → II → III → VI → IV → V, which corresponds to choice D.

Arrange the Events Listed Below in Order According to the Signal