Fig. 4: The hTR RNA stabilizes TERT to maintain the short primer–template duplex in the active site.
From: Zipper head mechanism of telomere synthesis by human telomerase
a Double-ring architecture of TERT and hTR. Upper, Domain architecture of TERT. TEN, telomerase essential N-terminal domain; TRBD, telomerase RNA-binding domain; FA and FB, fingers-A and fingers-B; Thumb, C-terminal extension (CTE) analogous to polymerase thumb subdomain. Lower, front and back views of the double-ring architecture of TERT and hTR. The domains are colored as in the upper panel. b Electrostatic surface potential of hTR-interacting sites of the TRBD subdomain of TERT. The two interacting surfaces of TERTTRBD with the t-PK and TWJ domains of hTR are highlighted with dashed red and magenta boxes, respectively (positive potential, blue; negative potential, red). The hTR RNA is shown in cartoon representation. c Interactions of the TWJ domain of hTR with the TERTTRBD and the histone H2A–H2B heterodimer. Proteins are shown in cylinder representation. d Close-up view of the interactions between TERTthumb and the t-PK and TWJ domains of hTR. TERTthumb is shown in electrostatic surface potential. e Comparison of root-mean-square-fluctuations (RMSFs) of TERT in the presence (green) and absence (red) of hTR. Domain architecture of TERT is shown below the figure. f Cross-correlation of TERT in the absence (upper) and presence (lower) of hTR. g Distance distributions between the zipper head residue Leu980 and three essential aspartate residues (Asp712, Asp868 and Asp869) at the catalytic center in the absence (orange) and presence (light blue) of hTR. h Overall view of the distance between the zipper head Leu980 and the catalytic center.
