Ribosome Binding Sites/Overview

A typical RBS sequence is located about 6 nucleotides upstream of a start codon in an mRNA. The ribosomal holoenzyme binds to both the RBS and the start codon. The start codon and everything downstream are translated by the ribosome.

A Ribosome Binding Site (RBS) is an RNA sequence found in mRNA to which ribosomes can bind and initiate translation. Translation initiation in bacteria almost always requires both an RBS sequence and a start codon. In the registry, protein coding sequences begin with the start codon. So, if you want to build a BioBrick system that produces a protein, you need to pick an RBS part and put it upstream of the protein coding sequence you want to translate. Note that an RBS is often defined as just that part of the mRNA sequence that binds to the ribosome, however, the surrounding sequence can also affect the translation initiation rate. Consequently, a BioBrick™ RBS part contains the classic RBS but sometimes some surrounding sequence also. See here for a more detailed explanation of how RBSs work.