title: Hammerhead ribozyme mechanism: a ribonucleotide 5' to the substrate cleavage site is not essential.
abstract: Three hammerhead ribozymes with triplet specificities for cleavage 3' of CUC, GUC, and GUA have been evaluated for their sensitivity to the substitution of thymidine or 2'-deoxyuridine at central nucleotide position 16.1 in the substrate triplet. All three ribozymes cleaved their respective substrates, containing uridine or the modifications, with comparable rates. This indicates that the 2'-hydroxy group at position 16.1 is not essential for activity even though X-ray structure analysis shows it participates in H-bonding interactions. These H-bonds were considered to be of functional significance because an earlier report had provided data that thymidine at position 16.1 is deleterious for catalytic activity [Yang, J.-H., Perreault, J.-P., Labuda, D., Usman, N., and Cedergren, R. (1990) Biochemistry 29, 11156-11160].
authors.affiliation: Max-Planck-Institut für Experimentelle Medizin, Göttingen, Germany.
authors.forename: A R
authors.initials: AR
authors.lastname: Kore
authors.forename: F
authors.initials: F
authors.lastname: Eckstein
mesh_terms: D003857:Deoxyuridine / Q000031:analogs & derivatives / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D016337:RNA, Catalytic / Q000737:chemistry / Q000378:metabolism*; D012265:Ribonucleotides / Q000737:chemistry / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D013936:Thymidine / Q000378:metabolism
chemical_list: C116559:2'-deoxy-2'-aminouridine; D016337:RNA, Catalytic; D012265:Ribonucleotides; D013936:Thymidine; D003857:Deoxyuridine