E (exit) site

Definition

The E (exit) site is a location on the ribosome where tRNAs, having donated their amino acids, are released from the ribosome. This site ensures the efficient progression of translation by making room for new tRNA molecules.

5 Must Know Facts For Your Next Test

1. The E site is one of three binding sites on the ribosome, alongside the A (aminoacyl) and P (peptidyl) sites.
2. tRNAs exiting from the E site have already transferred their amino acid to the growing polypeptide chain.
3. The movement of tRNAs from the P site to the E site is facilitated by translocation during protein synthesis.
4. Correct functioning of the E site is crucial for maintaining the fidelity and efficiency of translation.
5. Mutations affecting the E site can lead to errors in protein synthesis, potentially resulting in defective or nonfunctional proteins.

Related terms

A (aminoacyl) site:

The ribosomal binding site that holds an incoming tRNA with its attached amino acid.

P (peptidyl) site:

The ribosomal binding site that holds a tRNA carrying a growing polypeptide chain.

Translocation: The process by which tRNAs move from one ribosomal binding site to another during translation.