Kim, Nak-Kyoon Zhang, Qi Feigon, Juli 2024-01-20T10:05:02Z 2024-01-20T10:05:02Z 2021-09-05 2014-03 0305-1048 https://pubs.kist.re.kr/handle/201004/127044 Telomerase is a unique reverse transcriptase that maintains the 30 ends of eukaryotic chromosomes by adding tandem telomeric repeats. The RNA subunit (TR) of vertebrate telomerase provides a template for reverse transcription, contained within the conserved template/pseudoknot domain, and a conserved regions 4 and 5 (CR4/5) domain, all essential for catalytic activity. We report the nuclear magnetic resonance (NMR) solution structure of the full-length CR4/5 domain from the teleost fish medaka (Oryzias latipes). Three helices emanate from a structured internal loop, forming a Y-shaped structure, where helix P6 stacks on P5 and helix P6.1 points away from P6. The relative orientations of the three helices are Mg2+ dependent and dynamic. Although the three-way junction is structured and has unexpected base pairs, telomerase activity assays with nucleotide substitutions and deletions in CR4/5 indicate that none of these are essential for activity. The results suggest that the junction is likely to change conformation in complex with telomerase reverse transcriptase and that it provides a flexible scaffold that allows P6 and P6.1 to correctly fold and interact with telomerase reverse transcriptase. English OXFORD UNIV PRESS HYDROGEN-BONDS TRIPLE-HELIX STEM-LOOP BINDING PSEUDOKNOT ASSIGNMENT BIOMOLECULES TETRAHYMENA BIOGENESIS TOPOLOGY Structure and sequence elements of the CR4/5 domain of medaka telomerase RNA important for telomerase function Article 10.1093/nar/gkt1276 1 NUCLEIC ACIDS RESEARCH, v.42, no.5, pp.3395 - 3408 NUCLEIC ACIDS RESEARCH 42 5 3395 3408 scie scopus 000333093600054 2-s2.0-84899006963 Biochemistry & Molecular Biology Biochemistry & Molecular Biology Article HYDROGEN-BONDS TRIPLE-HELIX STEM-LOOP BINDING PSEUDOKNOT ASSIGNMENT BIOMOLECULES TETRAHYMENA BIOGENESIS TOPOLOGY