Broad-specificity mrna-rrna complementarity in efficient protein translation

Studies of synthetic,well-defined biomolecular systems can elucidate inherent capabilities that may be difficult to uncover in a native biological context. here,we used a minimal,reconstituted translation system from escherichia coli to identify efficient ribosome binding sites (rbss) in an unbiased,high-throughput manner. we applied ribosome display,a powerful in vitro selection method,to enrich only those mrna sequences which could direct rapid protein translation. in addition to canonical shine-dalgarno (sd) motifs,we unexpectedly recovered highly efficient cytosine-rich (c-rich) sequences that exhibit unmistakable complementarity to the 16s rrna of the small subunit of the ribosome,indicating that broad-specificity base-pairing may be an inherent,general mechanism for efficient translation. furthermore,given the conservation of ribosomal structure and function across species,the broader relevance of c-rich rbs sequences identified through our in vitro evolution approach is supported by multiple,diverse examples in nature,including c-rich rbss in several bacteriophage and plants,a poly-c consensus before the start codon in a lower eukaryote,and kozak-like sequences in vertebrates. © 2012 barendt et al.