Fig. 2: EM structure of the biogenesis module of human telomerase.
From: Zipper head mechanism of telomere synthesis by human telomerase
a Front and back views of the biogenesis module with protein factors colored as in Fig. 1. The two protein–protein interfaces between the two H/ACA units are highlighted with dashed magenta and red boxes, respectively. b, c Close-up views of the ACA (b) and H (c) boxes that are recognized by 3′ and 5′ dyskerins via sequence-specific interactions, respectively. The two dyskerin proteins are shown in electrostatic surface potentials (positive potential, blue; negative potential, red). d Close-up view of the CAB and BIO boxes that are recognized by TCAB1 and NHP2. TCAB1 and NHP2 are shown in ribbon representations, and residues important for the interactions are shown in stick model. e–g Structural comparison of the 3′- (f) and 5′- (g) H/ACA units of human telomerase with the canonical substrate-bound H/ACA RNP (e). The putative active site for pseudouridine synthases was designated with red star.
