FIG 3.

The assimilatory nitrate reduction system in P. putida KT2440. Average fitness values (n = 2) exhibited in the nitrate (green), nitrite (red), and ammonium (yellow) sole nitrogen source experiments. Shown are putative transporters, action of the NasST regulatory system, the assimilatory pathway, and the role of the bis-molybdopterin guanine dinucleotide (bis-MGD) cofactor. bis-MGD is the required cofactor for NarB (155). The fitness phenotypes for bis-MGD biosynthesis cluster together with the nitrate phenotypes and can be found in the interactive t-SNE visualization (Fig. I1 available at https://ppnitrogentsne.lbl.gov).