Figure 3.

Cft2 antagonizes Mpe1 binding to polymerase module

(A) Size exclusion chromatography with polymerase module, Cft2, and Mpe1, with (green) or without (blue) precleaved CYC1 RNA (pcCYC1). Top, chromatogram; middle two panels, Coomassie-stained SDS-PAGE of indicated fractions; and bottom, urea-PAGE of fluorescently labeled RNA from the indicated fractions. The gels are outlined in colors corresponding to the chromatograms. ^∗ denotes degradation products of Cft2.

(B) Cryo-EM map of the polymerase module in complex with Cft2(S). The yeast polymerase module interacting motif (yPIM) of Cft2 is colored in blue. The rest of Cft2, Mpe1, precleaved CYC1 RNA, Fip1, and Pap1 are not visible in the map.

(C and D) The yPIM of Cft2 (blue, cartoon and stick representation) inserts a conserved F537 residue into a hydrophobic pocket in Cft1 (green, surface representation) (C) and conserved Y549 and F558 residues into a hydrophobic pocket of Pfs2 (yellow, surface representation) (D).

See also Figure S3