C-GEM researchers investigated whether preventing the binding of ribosomal protein bS1 could improve ribosome orthogonality. A current, common strategy for generating orthogonal ribosomes involves controlling mRNA and ribosome interactions by modifying the Shine-Dalgarno and anti-Shine-Dalgarno sequences, the sequence that sits upstream of the start codon on mRNA and it’s ribosomal counterpart respectively. However, this modification does not produce perfectly orthogonal ribosomes, suggesting the presence of other mechanisms for translation initiation. The Cate lab hypothesized that ribosomal protein bS1, which aids mRNA shuttling to the ribosome, contributes to Shine-Dalgarno independent translation. This paper finds that blocking bS1 binding to the 30S ribosomal subunit does not produce orthogonality, raising important questions about what other translation initiation factors might be contributing to Shine-Dalgarno independent translation.
This work involved contributions from the Cate lab, including by undergraduates Minji Kim and Rebecca Bernstein.