P-site

The P-site (for peptidyl) is the second binding site for t-RNA in the ribosome. The other two sites are the A-site (aminoacyl), which is the first binding site in the ribosome, and the E-site (exit), which is the third and final binding site in the ribosome. L27 is located at the P-site as shown by affinity labeling. The P-site during translation holds the t-RNA which is linked to the growing polypeptide chain. When a stop codon is reached ending translation, the peptidyl-tRNA bond of the t-RNA located in the P-site is cleaved releasing the newly synthesized protein.

1. A.P. Czernilofsky et al., Proc.Natl.Acad.Sci. USA, Vol 71, pp 230–234, 1974, and FEBS Lett., Vol 63, pp 283–286, 1976.

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