Figure 3.

qPCR evaluation of genes encoding putative methionine transport components. qPCR was used to examine MtaR-dependent expression of putative methionine ABC transport genes (substrate-binding components). Melting curve analysis and agarose electrophoresis of PCR products were performed to ensure that each primer pair only produced a single amplicon. The ΔΔC_t quantification method was used to determine relative gene expression differences normalized to rpsL (housekeeping control) expression. metQ1 expression (open bars) and metQ2 expression (filled bars) were compared between strains. The comparisons were performed by calculating the gene expression ratios of DS101 (mtaR^-) or DS105 (DS101 complemented with a low-copy plasmid bearing the wild-type mtaR⁺ allele) to those of COH1.