Circularization of linear viroid RNA via 2′-phosphomonoester, 3′, 5′-phosphodiester bonds by a novel type of RNA ligase from wheat germ and Chlamydomonas

Yo Kikuchi, Kazimierz Tyc, Witold Filipowicz, Heinz L. Sänger, Hans J. Gross

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51 Citations (Scopus)


A novel type of RNA ligase activity in extracts of wheat germ or Chlamydomonas requires 2′,3′-cyclic phosphate and 5′-phosphate ends for ligation to form a 2′-phosphomonoester, 3′,5′-phosphodiester bond. Using 5′-32P-labeled linear PSTV, we demonstrate that RNase T1-nicked viroid predominantly forms -G3′-P2′-P-5′U-bonds. Natural linear PSTV, however, forms main--G3′-P2′-P-5′A-bonds upon enzymatic circularization. We show that natural linear PSTV RNA has nicks between C181 and A182, or between C348 and A349, and that consequently C181 and C348 carry 2′,3′-cyclophosphate termini.

Original languageEnglish
Pages (from-to)7521-7529
Number of pages9
JournalNucleic Acids Research
Issue number23
Publication statusPublished - 1982 Dec 11
Externally publishedYes


ASJC Scopus subject areas

  • Statistics, Probability and Uncertainty
  • Applied Mathematics
  • Health, Toxicology and Mutagenesis
  • Toxicology
  • Genetics(clinical)
  • Genetics

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