Figure 2 - full size

Figure 2.
FIG. 2. Structure of K. pneumoniae ALS. A shows a ribbon diagram of the overall structure of the resting enzyme tetramer, with the monomers colored green (monomer A), red (B), blue (C), and yellow (D). There is a vertical 2-fold axis of symmetry in this view. The asymmetric unit contains monomers A and B, whereas the active sites are at the AC and BD interfaces. Monomer A is shown in B, with cylinder representations of -helices (red) and -strands (turquoise) shown as arrows, connected by random coil (green). C and D compare the -domains of ALS (C) and AHAS (D), with secondary structure indicated as in B. The residues in contact with FAD (stick model, D) in AHAS and their structural equivalents in ALS (C) are shown in surface representation.