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Snapshots of the second-step self-splicing of Tetrahymena ribozyme revealed by cryo-EM.

ABSTRACT: Group I introns are catalytic RNAs that coordinate two consecutive transesterification reactions for self-splicing. To understand how the group I intron promotes catalysis and coordinates self-splicing reactions, we determine the structures of L-16 Tetrahymena ribozyme in complex with a 5'-splice site analog product and a 3'-splice site analog substrate using cryo-EM. We solve six conformations from a single specimen, corresponding to different splicing intermediates after the first ester-transfer reaction. The structures reveal dynamics during self-splicing, including large conformational changes of the internal guide sequence and the J5/4 junction as well as subtle rearrangements of active-site metals and the hydrogen bond formed between the 2'-OH group of A261 and the N2 group of guanosine substrate. These results help complete a detailed structural and mechanistic view of this paradigmatic group I intron undergoing the second step of self-splicing.

SUBMITTER: Li S

PROVIDER: S-EPMC10020454 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature

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Snapshots of the second-step self-splicing of Tetrahymena ribozyme revealed by cryo-EM.

Li Shanshan S Palo Michael Z MZ Zhang Xiaojing X Pintilie Grigore G Zhang Kaiming K

Nature communications 20230316 1

Group I introns are catalytic RNAs that coordinate two consecutive transesterification reactions for self-splicing. To understand how the group I intron promotes catalysis and coordinates self-splicing reactions, we determine the structures of L-16 Tetrahymena ribozyme in complex with a 5'-splice site analog product and a 3'-splice site analog substrate using cryo-EM. We solve six conformations from a single specimen, corresponding to different splicing intermediates after the first ester-transf ...[more]

PMID: 36928031

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Snapshots of the first-step self-splicing of Tetrahymena ribozyme revealed by cryo-EM.

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Project description: Not available

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