Novel RNA structural features of an alternatively splicing group II intron from Clostridium tetani
| Autor: | Bonnie A. McNeil, Steven Zimmerly |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Genetics
Splice site mutation Base Sequence biology GIR1 branching ribozyme RNA Splicing Molecular Sequence Data Ribozyme Exons Articles Group II intron Introns Clostridium tetani Mutation RNA splicing biology.protein Nucleic Acid Conformation RNA RNA Catalytic Group I catalytic intron RNA Splice Sites Mammalian CPEB3 ribozyme Base Pairing Molecular Biology VS ribozyme |
| Zdroj: | RNA. 20:855-866 |
| ISSN: | 1469-9001 1355-8382 |
| Popis: | Group II introns are ribozymes in bacterial and organellar genomes that function as self-splicing introns and as retroelements. Previously, we reported that the group II intron C.te.I1 of Clostridium tetani alternatively splices in vivo to produce five distinct coding mRNAs. Accurate fusion of upstream and downstream reading frames requires a shifted 5′ splice site located 8 nt upstream of the usual 5′ GUGYG motif. This site is specified by the ribozyme through an altered intron/exon-binding site 1 (IBS1–EBS1) pairing. Here we use mutagenesis and self-splicing assays to investigate in more detail the significance of the structural features of the C.te.I1 ribozyme. The shifted 5′ splice site is shown to be affected by structures in addition to IBS1–EBS1, and unlike other group II introns, C.te.I1 appears to require a spacer between IBS1 and the GUGYG motif. In addition, the mechanism of 3′ exon recognition is modified from the ancestral IIB mechanism to a IIA-like mechanism that appears to be longer than the typical single base-pair interaction and may extend up to 4 bp. The novel ribozyme properties that have evolved for C.te.I1 illustrate the plasticity of group II introns in adapting new structural and catalytic properties that can be utilized to affect gene expression. |
| Databáze: | OpenAIRE |
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