Figure 8.

Overview of eSTK control of transcription in the streptococci. Schematic diagram showing the signaling pathways involved in eSTK control of Group A Streptococci (GAS), Group B Streptococci (GBS) and S. pneumoniae regulatory factors mentioned in this text. In GAS and GBS the PASTA-containing eSTK is called Stk1, and in S. pneumoniae StkP. Stk1 from both GAS and GBS modulates the TCS regulator CovR in these species, whereas WalR has thus far only been shown to be phosphorylated by Stk1 in GAS. Similarly, StkP modulates the TCS regulators RR06 and RitR in S. pneumoniae. The question mark shown above RitR indicates that aside form StkP phosphorylation, regulation from other input signals has not been identified. The phosphorylation PTM is denoted by the circle with a “P.” Red circles indicate serine or threonine phosphorylation, whereas blue indicates aspartate phosphorylation. Virulence and other traits that the regulators control are also described. Transmembrane region (TM). The TCS histidine kinases CovS, WalK and HK06 have 2 TMs each that are not annotated here for purposes of simplicity.