The hammerhead ribozyme is a small catalytic RNA motif made up of three base-paired stems and a core of highly conserved, non-complementary nucleotides essential for catalysis. The X-ray crystallographic structure of a hammerhead RNA-DNA ribozyme-inhibitor complex at 2.6 A resolution reveals that the base-paired stems are A-form helices and that the core has two structural domains. The first domain is formed by the sequence 5'-CUGA following stem I and is a sharp turn identical to the uridine turn of transfer RNA, whereas the second is a non-Watson-Crick three-base-pair duplex with a divalent-ion binding site. The phosphodiester backbone of the DNA inhibitor strand is splayed out at the phosphate 5' to the cleavage site. The structure indicates that the ribozyme may destabilize a substrate strand in order to facilitate twisting of the substrate to allow cleavage of the scissile bond.
Three-dimensional structure of a hammerhead ribozyme.,Pley HW, Flaherty KM, McKay DB Nature. 1994 Nov 3;372(6501):68-74. PMID:7969422[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Pley HW, Flaherty KM, McKay DB. Three-dimensional structure of a hammerhead ribozyme. Nature. 1994 Nov 3;372(6501):68-74. PMID:7969422 doi:http://dx.doi.org/10.1038/372068a0
