<P> The RBS sequence affects both of these factors . </P> <P> The ribosomal protein S1 binds to adenine sequences upstream of the RBS . Increasing the concentration of adenine upstream of the RBS will increase the rate of ribosome recruitment . </P> <P> The level of complementarity of the mRNA SD sequence to the ribosomal ASD greatly affects the efficiency of translation initiation . Richer complementarity results in higher initiation efficiency . It is worth noting that this only holds up to a certain point - having too rich of a complementarity is known to paradoxically decrease the rate of translation as the ribosome then happens to be bound too tightly to proceed downstream . </P> <P> The optimal distance between the RBS and the start codon is variable - it depends on the portion of the SD sequence encoded in the actual RBS and its distance to the start site of a consensus SD sequence . Optimal spacing increases the rate of translation initiation once a ribosome has been bound . The composition of nucleotides in the spacer region itself was also found to affect the rate of translation initiation in one study . </P>

The ribosome binding site interacts with which specific molecule in the ribosome