Fig. 7.

Model of 5′UTR conformation and dimerization and the effects of tRNA^Lys3 and NCp7. The 2M and ΔDIS mutations in the 5′UTR promote the dimerization-incompetent and dimerization-competent conformations, respectively. The WT 5′UTR exists in equilibrium between both conformations. tRNA^Lys3 promotes the DIS-exposed monomer and kissing dimer but inhibits the formation of the extended dimer. NC enriches for the extended dimer conformation, irrespective of tRNA^Lys3 binding. Elevated Mg²⁺ promotes formation of the extended dimer in the absence of other factors.