Question

Once the SRP-ribosome complex is bound to the ER signal sequence and to the ribosome; what happens?

Answer 1

Once the SRP-ribosome complex is bound to the ER signal sequence and to the ribosome, the SRP detaches from the growing polypeptide chain, translation elongation resumes through a translocation channel, and elongation continues as the polypeptide begins to fold in the ER.

Step-by-step explanation:

Once the SRP-ribosome complex is bound to the ER signal sequence and to the ribosome, several steps occur:

1. The SRP detaches from the growing polypeptide chain, to be recycled.
2. Translation elongation resumes through a translocation channel; a signal peptidase in the RER membrane catalyzes co-translational hydrolysis of the signal peptide, which remains embedded in the RER membrane.
3. Elongation continues and the growing polypeptide begins to fold in the RER.

This process ensures that the newly synthesized protein is correctly targeted and inserted into the endoplasmic reticulum (ER), where it can undergo modifications and folding.