8T2P

5TU-t1 - heterodimeric triplet polymerase ribozyme

8T2P の概要

• エントリーDOI: 10.2210/pdb8t2p/pdb
• EMDBエントリー: 40984
• 分子名称: RNA (135-MER), RNA (152-MER) (2 entities in total)
• 機能のキーワード: polymerase, ribozyme, heterodimer, rna
• 由来する生物種: synthetic construct; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 92257.80

構造登録者

McRae, E.K.S.,Kristoffersen, E.,Gallego, I.,Hansen, K.,Holliger, P.,Andersen, E.S. (登録日: 2023-06-06, 公開日: 2024-01-24)

主引用文献

McRae, E.K.S.,Wan, C.J.K.,Kristoffersen, E.L.,Hansen, K.,Gianni, E.,Gallego, I.,Curran, J.F.,Attwater, J.,Holliger, P.,Andersen, E.S.
Cryo-EM structure and functional landscape of an RNA polymerase ribozyme.
Proc.Natl.Acad.Sci.USA, 121:e2313332121-e2313332121, 2024

PubMed Abstract: The emergence of an RNA replicase capable of self-replication is considered an important stage in the origin of life. RNA polymerase ribozymes (PR) - including a variant that uses trinucleotide triphosphates (triplets) as substrates - have been created by in vitro evolution and are the closest functional analogues of the replicase, but the structural basis for their function is poorly understood. Here we use single-particle cryogenic electron microscopy (cryo-EM) and high-throughput mutation analysis to obtain the structure of a triplet polymerase ribozyme (TPR) apoenzyme and map its functional landscape. The cryo-EM structure at 5-Å resolution reveals the TPR as an RNA heterodimer comprising a catalytic subunit and a noncatalytic, auxiliary subunit, resembling the shape of a left hand with thumb and fingers at a 70° angle. The two subunits are connected by two distinct kissing-loop (KL) interactions that are essential for polymerase function. Our combined structural and functional data suggest a model for templated RNA synthesis by the TPR holoenzyme, whereby heterodimer formation and KL interactions preorganize the TPR for optimal primer-template duplex binding, triplet substrate discrimination, and templated RNA synthesis. These results provide a better understanding of TPR structure and function and should aid the engineering of more efficient PRs.

PubMed: 38207080
DOI: 10.1073/pnas.2313332121

実験手法

ELECTRON MICROSCOPY (5 Å)