title: Identification of important bases in a single-stranded region (SSrC) of the hepatitis delta (delta) virus ribozyme.
abstract: Models for the secondary structure of genomic and antigenomic self-cleaving RNAs of human hepatitis delta (delta) virus (HDV) have been proposed by several groups. Our recent results support a pseudoknot structure and have allowed us to identify functionally important nucleotides in single-stranded regions [nucleotides 726-731 (SSrA) and nucleotides 762-766 (SSrB)]. For the identification of the important residues in the remaining single-stranded region, nucleotides 708-715 (SSrC), of the genomic HDV ribozyme, we made derivatives with a single-base substitution in the SSrC region. To screen inactive mutants rapidly, we use a simplified in-vitro selection method. Among the various base substitutions in mutants in the SSrC, U708A, C709(A/G/U) and G713C variants had less than 10% of the cleavage activity of the wild-type SSrC (HDV86). By analyzing the self-cleavage activities of various mutants, we determined the base requirements for SSrC as 5'-(U/C/G)-C-N-N-(C/A/G)-(G/A/U)-N-N-3'.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Kawakami
authors.forename: P K
authors.initials: PK
authors.lastname: Kumar
authors.forename: Y A
authors.initials: YA
authors.lastname: Suh
authors.forename: F
authors.initials: F
authors.lastname: Nishikawa
authors.forename: K
authors.initials: K
authors.lastname: Kawakami
authors.forename: K
authors.initials: K
authors.lastname: Taira
authors.forename: E
authors.initials: E
authors.lastname: Ohtsuka
authors.forename: S
authors.initials: S
authors.lastname: Nishikawa
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry; D003698:Hepatitis Delta Virus / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012326:RNA Splicing; D016337:RNA, Catalytic / Q000737:chemistry*; D012367:RNA, Viral / Q000737:chemistry*
chemical_list: D016337:RNA, Catalytic; D012367:RNA, Viral; D004247:DNA