The recognition of nucleotide residues A1531 and A1534 by Era in stereo. (A) Interactions between A1531 and Era. (B) Interactions between A1534 and Era. Protein and nucleotide residues are shown as stick models in atomic colors (C, green; N, blue; O, red; and P, orange). Protein backbone is shown as a cartoon (helices as spirals, strands as arrows, and loops as tubes), and protein surface is shown with 50% transparency. This figure was originally published in Reference [13].