8T2P
5TU-t1 - heterodimeric triplet polymerase ribozyme
Summary for 8T2P
| Entry DOI | 10.2210/pdb8t2p/pdb |
| EMDB information | 40984 |
| Descriptor | RNA (135-MER), RNA (152-MER) (2 entities in total) |
| Functional Keywords | polymerase, ribozyme, heterodimer, rna |
| Biological source | synthetic construct More |
| Total number of polymer chains | 2 |
| Total formula weight | 92257.80 |
| Authors | McRae, E.K.S.,Kristoffersen, E.,Gallego, I.,Hansen, K.,Holliger, P.,Andersen, E.S. (deposition date: 2023-06-06, release date: 2024-01-24) |
| Primary citation | 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 Cited by 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: 38207080DOI: 10.1073/pnas.2313332121 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (5 Å) |
Structure validation
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