The structure of fadL mRNA and its interactions with RybB sRNA.

Small bacterial RNAs (sRNAs) regulate translation by pairing with complementary sequences in their target mRNAs, in a process which is often dependent on the Hfq protein. Here, the secondary structure of a 95-nt long fragment of Salmonella fadL mRNA containing RybB sRNA binding site in the coding region was analyzed. The data indicated local rearrangements in this mRNA structure after the annealing of RybB. The filter retention data had shown that Hfq bound both RybB and the fadL mRNA fragment with tight affinities. Moreover, Hfq increased the rate of RybB annealing to fadL mRNA. These data indicate that Hfq directly participates in RybB interactions with the fadL mRNA.