Many proteins contain a specialized stretch of amino acids that are recognized by a protein complex called the signal recognition particle. Which of the following best describes the function of this complex during the synthesis of secretory proteins?

Question

Quizplus · Accepted Answer

The signal recognition particle (SRP) interacts with the signal sequence at the amino terminus of the nascent polypeptide, pausing translation and directing the ribosome to the endoplasmic reticulum membrane for protein synthesis. Membrane-bound and secreted proteins are synthesized by ribosomes attached to the membranes of the ER. As synthesis of these types of proteins begins a complex on the ER called the signal recognition particle (SRP) engages the signal peptide of the newly synthesizing protein. Since protein synthesis proceeds from the N-terminus to the C-terminus, the SRP is recognizing the signal sequence at the N-terminus of the protein.

Many Proteins Contain a Specialized Stretch of Amino Acids That