BIOL 201 Lecture Notes - Lecture 19: Sec61, Isoleucine, Protease
Document Summary
Making amino acids at n terminus of the proteins. Er proteins are often translated by er-bound ribosomes. Dots right adjacent to the membrane: ribosomes physically attached to the er membrane. Feeding its protein polypeptide directly through er by the channel. Cotranslational translocation in initiated by signal recognition particles. Ribosome starts out of a cytoplasm and it is bound to mrna --> translating. The first bit of polypeptide that is produced at the very n-terminus, there"s a zip code (the signal sequence-particular code of amino acids that tells cells the proteins need to go into the lumen) As that signal sequence merges (very hydrophobic) it is going to attract proteins with hydrophobic binding domains. Hydrophobic groove will bind to signal sequence and capture it. Recognized signal that is ready to move to the membrane of er. Srps dock the ribosome on the er membrane. In the gtp state, these two particles like to interact, so they stick together.
