Novel RNA-binding protein YebC enhances translation of proline-rich amino acid stretches in bacteria

Abstract

The ribosome employs a set of highly conserved translation factors to efficiently synthesise proteins. Some translation factors interact with the ribosome in a transient manner and are thus challenging to identify. However, proteins involved in translation can be specifically identified by their interaction with ribosomal RNAs. Using a combination of proteomics approaches, we identified novel RNA binding proteins in the pathogenic bacteriumStreptococcus pyogenes. One of these, a universally conserved protein YebC, was shown to transiently interact with 23S rRNA near the peptidyl-transferase centre. Deletion ofyebCmoderately affected the physiology and virulence ofS. pyogenes. We performed ribosome profiling and detected increased pausing at proline-rich amino acid stretches in the absence of functional YebC. Further results obtained within vivoreporters andin vitrotranslation system suggest that YebC is a novel translation factor required for efficient translation of proteins with proline-rich motifs.