Figure 6.
Conserved RNA polymerase III-specific domains. Top and front backbone views of RNA polymerase II in S.cerevisiae, prepared with the RASMOL software (http://www.umass.edu/microbio/rasmol/), using atomic coordinates 1WCM (22) at the PDB Protein Data Bank. The position of the three main RNA polymerase III-specific domains are shown as coloured thick lines on the RNA polymerase II structure. They correspond to the C-half of Rpc17, shown in green (positions 103–212, corresponding to 105–171 in Rpb7, see Supplementary Data S5), the C-half of Rpc25, shown in orange (positions 71–161, corresponding to 150–221 in Rpb4), and to N-terminal (red) and C-terminal (blue) motifs of Rpc1, delimitated by positions 117–227 and 1170–1292 (corresponding to 117–207 and 1148–1304 in Rpb1). The equivalence between Rpc1 and Rpb1 is based on the sequence alignments shown as Supplementary Data S5. The hypothetical localization of the Rpc37, Rpc53 and Rpc31, Rpc34 and Rpc82 groups of subunits is suggested by dashed ovals (see text for explanations).