DOMAIN MOTIONS OF CLASS I RELEASE FACTOR INDUCED BY BINDING WITH CLASS II RELEASE FACTOR IN <i>Euplotes octocarinatus</i>
The binding of two factors (eRF1 and eRF3) is essential for fast kinetics of the termination of protein translation. The C terminal domain of eRF1 is known to interact with the C domain of eRF3. Eo eRF1b contains two highly conserved tryptophan side chains (W 11 and W 373), W 11 located in Eo eRF1b N domain and W 373 located in EoeRF1b C domain. Fluorescence spectrophotometry was used to study the interactions of the proteins. When binding with Eo eRF3Cm6, the emission peak of Eo eRF1b is blue shifted, while the emission peak of Eo eRF1bC has no notable change. Our results suggest that the eRF1-eRF3 interaction induces the N and C domain of eRF1b to be close to each other.