Response of Streptococcus pyogenes to feast and famine conditions

In this report, we identify the CodY protein and the product of the activated RelA protein, (p)ppGpp, from Streptococcus pyogenes as pleiotropic regulatory factors that direct nutritional status-dependent transcriptional expression of specific regulatory genes, virulence factors, transporters, and metabolic enzyme genes. Real-time reverse transcription PCR was used to determine the extent to which inactivation of codY and relA affects the mRNA levels of the target genes under different nutritional conditions using complex and chemically defined media.