Figure 8.

Protein complexes of the P_II regulatory system in S. elongatus according to availability of ammonium in the cell, and their corresponding functional consequences. The frequencies of the different chains in the various forms are based on the levels of the proteins in the cell found in proteomic studies (Table 1). The P_II trimer has been colored blue, PipX and its C-terminal helices are red, PlmA dimers have their DNA binding domains yellow or orange and their dimerization domains in two hues of green, NAGK is shown as a purple crown, and the regulatory and DNA binding domains of NtcA are given dark and light shades of blue, respectively.