These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Non-cognate template usage and alternative priming by a group II intron-encoded reverse transcriptase.
    Author: Morozova T, Seo W, Zimmerly S.
    Journal: J Mol Biol; 2002 Feb 01; 315(5):951-63. PubMed ID: 11827468.
    Abstract:
    Group II introns are retroelements that site-specifically insert into DNA through homing. They are also implicated in related phenomena such as ectopic site insertions and precise intron deletions, but little is known about how group II intron reverse transcriptases (RTs) interact with non-cognate substrates. Here we show that wild-type aI2 RT readily reverse transcribes non-cognate RNAs in mitochondrial RNP particles when the aI2 intron structure is misfolded. In two closely related priming mutants, 1degree2(DeltaD5) and 1(+)2(DeltaD5), which contain wild-type RT but a disrupted intron structure, the RT has substantially lost specificity for aI2 RNA and copies multiple RNAs present in the RNP particles, using an alternative priming mechanism. The RT in 1degree2(DeltaD5) RNP particles can also copy exogenous RNAs but unlike the endogenous templates, a complementary primer is required, suggesting that the alternative priming event is specific to RT-RNA interactions formed in vivo. Alternatively primed cDNAs from strains 1degree2(DeltaD5), 1(+)2(DeltaD5) and 1degree2(P714T) (containing the mutation P714T in the RT) do not use homing site DNA as a primer, but appear to utilize a non-complementary DNA primer of approximately ten nucleotides. The alternative priming mechanism and reverse transcription of non-cognate templates has implications for in vivo reverse transcription of non-intronic RNAs, which is expected to occur during intron deletions and other retroprocessing events.
    [Abstract] [Full Text] [Related] [New Search]