FIG 3.

MaeK regulates malate-dependent expression of maePE. (A) WT, MaeK^–, and MaeK^r strains were grown in C medium supplemented with 0.5% malate until exponential phase (OD₆₀₀ of 0.2). Total RNA was isolated and used for real-time RT-PCR analysis of maeP and maeE transcripts. (B) WT bacteria were grown in C medium supplemented with 0.5% malate as described before. Total RNA was isolated and used for real-time RT-PCR analysis of maeK and maeR transcripts. Data presented for all genes are the ratios of transcript abundance in modified medium to that of unmodified C medium and represent the means and standard deviations from 3 biological samples, each analyzed in triplicate.