title: Fixation and accumulation of thermotolerant catalytic competence of a pair of ligase ribozymes through complex formation and cross ligation.
abstract: In the early stages of the hypothetical RNA world, some primitive RNA catalysts (ribozymes) may have emerged through self-assembly of short RNA oligomers. Although they may be unstable against temperature fluctuations and other environmental changes, ligase ribozymes (ribozymes with RNA strand-joining activity) may resolve structural instability of self-assembling RNAs by converting them to the corresponding unimolecular formats. To investigate this possibility, we constructed a model system using a cross-ligation system composed of a pair of self-assembling ligase ribozymes. Their abilities to act as catalysts, substrates, and a cross-ligation system were analyzed with or without thermal pretreatment before the reactions. A pair of self-assembling ligase ribozymes, each of which can form multiple conformations, demonstrated that thermotolerance was acquired and accumulated through complex-formation that stabilized the active forms of the bimolecular ribozymes and also cross-ligation that produced the unimolecular ribozymes.
authors.affiliation: Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Moto-oka 744, Fukuoka 819-0395, Japan.
authors.forename: Nana
authors.initials: N
authors.lastname: Isomoto
authors.forename: Yuri
authors.initials: Y
authors.lastname: Maeda
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tanaka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Furuta
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Ikawa
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000235:genetics / Q000378:metabolism; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D011130:RNA Ligase (ATP) / Q000235:genetics* / Q000378:metabolism; D016337:RNA, Catalytic / Q000235:genetics* / Q000378:metabolism
chemical_list: D009841:Oligonucleotides; D016337:RNA, Catalytic; D011130:RNA Ligase (ATP)