Supplementary Data 2: Transcriptional regulation by σ factor phosphorylation in bacteria

ECF σ factors and STKs retrieved during this study. The ECF group is only shown for groups known to be linked to STKs (ECF43, ECF59 and ECF60). ‘Length extended region’ refers to the length of the region between dashed lines in Fig. 3b. ‘aa63’ refers to the amino acid in the position equivalent to T63 in EcfP. ‘DAED’ refers to the amino acids that occupy the same position as consensus DAED in canonical ECFs and STTA in EcfP. The ‘98% identity group’ groups together the pairs of ECF-STK with a combined identity of ≥98% (see Methods). One example from each 98% identity group was chosen for the phylogenetic tree in Fig. 3a.