Comparison of the crystallographic structure of yeast RNAPII and the integrative model of human RNAPII. I, a–d, atomic representations of the integrative model of H-RNAPII and the reference structure in two views; the reference structure is composed of human subunits individually superposed on their orthologs in the yeast RNAPII structure. The configuration of the H-RNAPII subunits (a and c) is very similar to that in the reference structure (b and d); the Cα RMSD is only 11.4 Å. II, e–h, coarse representations of the H-RNAPII model (e and g) and the reference structure (f and h) in the same two views as in a–d further illustrate the high similarity between the model and the reference. In the coarse representation, sets of 30 contiguous residues are shown as a single bead. III, i and j, protein contact maps for the H-RNAPII model and the reference structure (white, no contact; gray, weak contact; black, contact). The maps are essentially identical, differing only in the interactions of Rpb6 with Rpb2 and Rpb3, and Rpb1 with Rpb12.