A curved RNA helix incorporating an internal loop with G·A and A·A non-Watson–Crick base pairing Journal Article uri icon



  • ; The crystal structure of the RNA dodecamer 5′-GGCC(GAAA)GGCC-3′ has; been determined from x-ray diffraction data to 2.3-Å 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° from end to end and the diameter is narrowed; by 24% in the internal loop. A Mn; 2+; 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; Mn; 2+; location corresponds to a metal binding site observed; in the hammerhead catalytic RNA.;

publication date

  • November 12, 1996

has restriction

  • green

Date in CU Experts

  • February 20, 2014 10:14 AM

Full Author List

  • Baeyens KJ; De Bondt HL; Pardi A; Holbrook SR

author count

  • 4

Other Profiles

International Standard Serial Number (ISSN)

  • 0027-8424

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

Additional Document Info

start page

  • 12851

end page

  • 12855


  • 93


  • 23