J. Kawakami et al., IDENTIFICATION OF IMPORTANT BASES IN A SINGLE-STRANDED REGION (SSRC) OF THE HEPATITIS-DELTA (DELTA) VIRUS RIBOZYME, European journal of biochemistry, 217(1), 1993, pp. 29-36
Models for the secondary structure of genomic and antigenomic self-cle
aving RNAs of human hepatitis delta (6) 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 76
2-766 (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 substitut
ion in the SSrC region. To screen inactive mutants rapidly, we use a s
implified in-vitro selection method. Among the various base substituti
ons 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 deter
mined the base requirements for SSrC as 5'-(U/C/G)-C-N-N-(C/A/G)-(G/A/
U)-N-N-3'.