Extended Data Fig. 2: Structural details of TtCST.
From: Structure of Tetrahymena telomerase-bound CST with polymerase α-primase
a, Domain organization of TtCST subunits. Invisible regions in the cryo-EM map are shown as dashed boxes. Intermolecular interactions are indicated as grey shading. b, Ribbon diagrams of TtCST subunits/domains with secondary-structure elements labelled. Unmodelled regions are shown as dashed lines. Crystal structure of Ten1–Stn1 OB23 (PDB 5DOI) is shown in grey and overlaid with the cryo-EM structure for comparison. c, Ribbon representation of TtCST structure with individual OB domain coloured as indicated. d, Close-up view of the interface between Ctc1 OB-C and Stn1 OB. Salt bridge and hydrogen-bonding interactions are shown as dashed yellow lines. e, Two arginine sidechains on Stn1 OB (ribbon) clamp D499 on Ctc1 OB-C (electrostatic surface). f, g, Detailed interactions between Stn1 OB and Ten1. h, Close-up views of the cryo-EM densities of the interfaces between CST subunits (Fig. 1e, Extended Data Fig. 2d–g). i, Overall view of the interface between TtCST and TERT–TER. j–l, Close-up views of interactions between TtCST and TERT–TER as indicated in dashed boxes in h. These interactions stabilize TtCST in the predominant conformation.
