Fig. 1.

Reconstruction of NAD metabolism in Bordetellae and the proposed role of Bug69 and Bug27 as Qa‐specific solute binding proteins. Pathway reactions are denoted by black arrows. The initial two steps of de novo NAD biosynthesis, missing in most Bordetellae, including Bordetella pertussis, are depicted in gray. The proposed role of Bug69 and Bug27 as Qa binders is shown. Uptake of pyridines (dotted black arrows) is by unknown mechanisms. Metabolites and enzyme abbreviations (not introduced in the main text). NadD (NaMNAT), nicotinate adenylyltransferase [43]; NadE, NAD synthetase [44]; NMN, nicotinamide mononucleotide; PncC, nicotinamide mononucleotide deamidase [45]; R5P, ribose‐5‐phosphate; PrsA, PRPP synthetase; Other abbreviations: IM, inner membrane; OM, outer membrane; P, periplasm.