Ciliates Are Genetic-Code Deviants

Traditional stop codons have a double meaning in the protozoans' mRNA, sometimes calling for an amino acid during translation.

Sep 30, 2016
Karen Zusi

© KIMBERLY BATTISTA

STOP AND GO SIGNALS

Certain ciliates use traditional stop codons ambiguously during translation. Sometimes these three-base-long RNA sequences code for an amino acid (green, left), and sometimes induce translation termination (red, right). Researchers propose that at the end of the mRNA coding sequence, the ribosome bumps up against proteins involved in termination—namely, eukaryotic release factors (eRF1 and eRF3) and poly(A) binding proteins (PABP)—thereby indicating that a stop codon means stop.

Read the full story.