It is unknown how alterations in the binding region of a UTR affect the protein expression regulated by an sRNA. The marine bacterium V. fischeri is a squid symbiont capable of producing bioluminescence. The current hypothesis is that differences in the litR sRNA-UTR complex result in different binding affinity for the regulatory protein Qrr1, resulting in varying bioluminescence between strains. Investigating the effect of UTR alterations will lead to increased knowledge in post-transcriptional protein regulation.