Figure 2.

Architecture of the Pab1020 homodimer. (A) Domain structure of Pab1020. The domains of Pab1020 are colored as follows: N-terminal domain, red; catalytic domain, green; dimerization domain, blue; C-terminal domain, orange. At left is a view facing the active site, and at right the molecule has been rotated by 90° around the axis shown. (Below) Schematic diagram of the domain boundaries. Locations of the conserved motifs I, III, IIIA, IV, and V of the nucleotidyl transferase superfamily are shown in dark green. (B) Molecule A is shown in green and molecule B in red as cartoons, and the molecules of AMPPNP as ball-and-stick models. The diagram demonstrates the “clamp” formation of the N-terminal domains and the cofactor analogs are highlighted. This figure, as well as Figures 3 and 5 were prepared with BOBSCRIPT (Esnouf 1997).