Figure 1. Scheme of Herbaspirillum seropedicae NifA domains. Numbers indicate the amino acid position on the primary structure. The N-terminal GAF domain, central domain, and C-terminal domain are indicated as open rectangles. The ATP-binding motifs, located in the central domain, and the helix-turn-helix (HTH) motif in the C-terminal domain are indicated as gray rectangles, and were predicted using the ScanProsite tool (http://prosite.expasy.org/scanprosite) (29) and Gym2.0 (30), respectively. Point-mutations (K22V, G25E, T160E, M161V, L172R, A215D, Q216I, and S220I) are indicated by gray triangles in the N-terminal GAF and central domains of NifA.
