title: Retrotransposon Ty1 RNA contains a 5'-terminal long-range pseudoknot required for efficient reverse transcription.
abstract: Ty1 retrotransposon RNA has the potential to fold into a variety of distinct structures, mutation of which affects retrotransposition frequencies. We show here that one potential functional structure is located at the 5' end of the genome and can assume a pseudoknot conformation. Chemoenzymatic probing of wild-type and mutant mini-Ty1 RNAs supports the existence of such a structure, while molecular genetic analyses show that mutations disrupting pseudoknot formation interfere with retrotransposition, indicating that it provides a critical biological function. These defects are enhanced at higher temperatures. When these mutants are combined with compensatory changes, retrotransposition is restored, consistent with pseudoknot architecture. Analyses of mutants suggest a defect in Ty1 reverse transcription. Collectively, our data allow modeling of a three-dimensional structure for this novel critical cis-acting signal of the Ty1 genome.
authors: Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
authors: Qing
authors: Q
authors: Huang
authors: Katarzyna J
authors: KJ
authors: Purzycka
authors: Sabrina
authors: S
authors: Lusvarghi
authors: Donghui
authors: D
authors: Li
authors: Stuart F J
authors: SF
authors: Legrice
authors: Jef D
authors: JD
authors: Boeke
mesh_terms: D009154:Mutation; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D012313:RNA / Q000737:chemistry* / Q000378:metabolism; D012331:RNA, Fungal / Q000737:chemistry* / Q000378:metabolism; D018626:Retroelements; D048348:Reverse Transcription; D012441:Saccharomyces cerevisiae / Q000235:genetics
chemical_list: D012331:RNA, Fungal; D018626:Retroelements; D012313:RNA