title: A small metalloribozyme with a two-step mechanism.
abstract: An RNA molecule consisting of an asymmetric internal loop of six nucleotides can be rapidly and specifically cleaved by Pb2+ in the presence of Mg2+. The 5' cleavage product terminates with a 3' phosphomonoester generated from a 2',3'-cyclic phosphodiester reaction intermediate. This two-step reaction mechanism resembles that of many protein ribonucleases but has not previously been observed for reactions catalysed by RNA.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309.
authors.forename: T
authors.initials: T
authors.lastname: Pan
authors.forename: O C
authors.initials: OC
authors.lastname: Uhlenbeck
mesh_terms: D001483:Base Sequence; D002384:Catalysis; D007700:Kinetics; D007854:Lead / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D008667:Metalloproteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016337:RNA, Catalytic / Q000378:metabolism*; D012360:RNA, Transfer, Phe / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism
chemical_list: D008667:Metalloproteins; D016337:RNA, Catalytic; D012360:RNA, Transfer, Phe; D007854:Lead; D008274:Magnesium