Figure 3.

Primary-sequence and structural model of the E. durans IPLA655 tyrS mRNA leader region upstream the start of the coding region. The specifier (UAC), the Tbox sequence, and other highly-conserved motifs typical of genes regulated by tRNA-mediated antitermination appear highlighted in boxes. Sequence between arrows can adopt two alternative mutually exclusive structure conformations: terminator and antiterminator (stabilized by the cognate tRNA in absence of tyrosine). A transcriptional fusion of the tyrS promoter and the leader region with a deletion of the TBox-Terminator region (P_tyrS^Δ) was made (dashed line) to probe the role of the Tbox in the mechanism of tyrosine sensing