Fig. 5
From: Cell cycle control and environmental response by second messengers in Caulobacter crescentus
Diagram of our second messenger model. Glutamine (Gln) acts as the nitrogen signal, which regulates the phosphorylation state of PTS Ntr enzymes. Solid black arrows represent conversion between molecular species. Solid purple lines indicate transfer of phosphoryl groups between species. Phosphoryl transfer is reversible. Dashed lines represent allosteric influences on reaction rates (an arrow-head represents activation and a bar-head represents inhibition). Dashed line 1 indicates product-inhibition based on cdG binding to the I-site of DGCs. Dashed line 2-1 indicates that phosphorylated NPr indirectly activates the synthase activity of SpoT, and dashed line 2-2 indicates that phosphorylated EIIA Ntr directly inhibits the hydrolase activity of SpoT