Fig 8. c-di-GMP–RavS binding promotes the specificity of the RavS–RavR phosphotransfer to control the bacterial lifestyle transition between swimming and virulence.

Left panel: During infection, RavA–RavR phosphotransfer is necessary to control bacterial virulence, whereas RavS is maintained at a low phosphorylation level. c-di-GMP binds to RavS to enhance the phosphotransfer to the REC domain of RavR, which acts as a phosphate sink. Right panel: During bacterial swimming, the level of phosphorylated RavS is high. The EAL domain of RavR is activated and degrades the c-di-GMP binding to RavS. This process decreases RavS-RavR phosphotransfer and promotes an increase in the RavS~P level to regulate flagella development. TrM: transmembrane helix. DHp: dimerization and histidine phosphotransfer domain. CA: catalytic and ATP binding domain. REC: receiver domain. P in the red circle represents the phosphoryl group. Grey dashed arrows or terms indicate that the biochemical processes were inactivated.