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: A curved RNA helix incorporating an internal loop with G.A and A.A non-Watson-Crick base pairing.
    Author: Baeyens KJ, De Bondt HL, Pardi A, Holbrook SR.
    Journal: Proc Natl Acad Sci U S A; 1996 Nov 12; 93(23):12851-5. PubMed ID: 8917508.
    Abstract:
    The crystal structure of the RNA dodecamer 5'-GGCC(GAAA)GGCC-3' has been determined from x-ray diffraction data to 2.3-A resolution. In the crystal, these oligomers form double helices around twofold symmetry axes. Four consecutive non-Watson-Crick base pairs make up an internal loop in the middle of the duplex, including sheared G.A pairs and novel asymmetric A.A pairs. This internal loop sequence produces a significant curvature and narrowing of the double helix. The helix is curved by 34 degrees from end to end and the diameter is narrowed by 24% in the internal loop. A Mn2+ ion is bound directly to the N7 of the first guanine in the Watson-Crick region following the internal loop and the phosphate of the preceding residue. This Mn2+ location corresponds to a metal binding site observed in the hammerhead catalytic RNA.
    [Abstract] [Full Text] [Related] [New Search]