(A) Schematic of SAM binding to the SAM aptamer, which induces folding, dimerization, and fluorogenic activation of Corn.
(B) Each indicated transducer sequence was tested for its ability to mediate SAM-induced fluorescence. In vitro transcribed Corn-SAM sensor RNA (1 μM) was incubated with 10 μM DFHO and 0.1 mM SAM for 1 h at 37°0. Fluorescence was measured (ex 505 nm; em 545 nm). The optimal transducer is indicated in a black-lined box. Mean and SEM values are shown in the plot (n = 3). *** P = 0.0004 (Transducer 1), ** P = 0.0010 (Transducer 2), ** P = 0.0067 (Transducer 5), *** P = 0.0004 (Transducer 9)