Effect of the length of antisense RNA on bacterial enzyme production

Antisense RNA molecules for the beta-galactosidase enzyme of E. coli and the urease enzyme of Proteus vulgaris were synthesized using the polymerase chain reaction. The artificial genes were designed to produce single stranded RNA molecules complementary to various lengths of the 5’ end of the messenger RNA molecules of the two bacterial enzymes. Four different antisense RNA molecules for each enzyme were synthesized to be complementary to the messenger RNA molecule of beta-galactosidase each from 30 nucleotides upstream from the initial AUG codon and binding to the Shine-Dalgarno sequence. For the beta galactosidase messenger RNA of E. coli, the antisense RNA molecules were 76, 119, 160 and 210 nucleotides in length. For the urease messenger RNA of Proteus vulgaris, the antisense RNA molecules were 51, 120, 174, and 226 nucleotides long. Binding of the antisense RNA to the messenger RNA interfered with the translation of the messenger RNA to produce bacterial enzymes. As the antisense RNA molecules for the E. coli beta-galactosidase messenger RNA molecules increased in length, the production of the enzyme increased from 38.8%, to 65.2%, to 85.2% to 100% of the control. As the antisense RNA molecules for the Proteus vulgaris urease messenger RNA molecules increased in length, the production of the enzyme increased from 54.0%, to 65.9%, to 74.6%, to 80.4% of the control. These results suggest that the smaller in length the antisense RNA is; the more effective it is at inhibiting translation of the mRNA molecules of these two enzymes in these two bacteria