Given that translation through the TURBS up to the termination-reinitiation window is a prerequisite for efficient reinitiation [11] , one can speculate that mfold 2 is the biologically relevant fold, and that destabilisation of the central stem of mfold 1 (stem 2) would have little effect on the reinitiation process. To test this hypothesis we created destabilising mutations within either arm of stem 2 (chosen to avoid disruption of the 18S rRNA complementary region) in the context of the p2luc-BM2-204 parental plasmid (which encodes the minimal required region for termination-reinitiation [11] ). The mutations created were of either 2 or 3 nt to control for context effects on the BM2 AUG, creating the arm 1 mutants p2luc-BM2A1-xnt, and the arm 2 mutants p2luc-BM2A2-xnt (where x = the number of nucleotides mutated). We also prepared double mutants (A1/2-xnt) to create a pseudowild-type structure where base-pairing between the two arms is restored. In the context of both the 2 nt and 3 nt mutations, substitution of bases in arm 1 abolished terminationreinitiation, however substitution of the bases at the bottom of arm 2 had little effect on BM2fluc synthesis relative to the BM2-204 control. The double pseudowild-type mutation also demonstrated abolition of BM2fluc expression ( Figure 8A ). Taken together these results suggest that the structure presented in mfold 1 is unlikely to play a role in termination-reinitiation as disruption of arm 2 of stem 2 has little effect on BM2 translation, and no restoration of BM2 synthesis was observed in the pseudowild-type construct.