Poster abstracts

Poster number 47 submitted by Daomin Qin

Isolation and characterization of 16S rRNA mutations which will cause spurious initiation

Daoming Qin (OSBP), Kurt Fredrick (OSBP and Department of Microbiology)

Abstract:
In bacteria, initiation of translation is kinetically controlled by factors IF1, IF2, and IF3, which work in conjunction with the 30S subunit to ensure accurate selection of the initiator tRNA (fMet-tRNA(fMet)) and the start codon. Here we randomly mutate the 16S rRNA gene and isolated several mutations which can cause spurious initiaton from noncognate start codon. The effects of these mutation were quantified in vivo. Interestingly, several mutations were clustering at helix 44, near IF1 biding site. We purified the mutant 30S and showed that these helix 44 mutations indeed decrease IF1 binding. Currently, we are trying to understand whether the spurious initiation in vivo is due to decreased IF1 binding.

Keywords: ribosome, IF1, translation initiation