Fig. 2. In vitro editing using psbL and ndhB mRNAs with substitution mutations. (A) Sequences of wild-type (WT) and mutant (5M and 3M) psbL and ndhB mRNAs. Sequences of 22 nt upstream and 9 nt downstream of the respective editing sites are shown. Substitutions by a vector sequence are underlined. KS represents the sequence of the KS primer annealing region. WT sequences were from Shinozaki et al. (1986). (B) In vitro editing activity of mutant psbL and ndhB mRNAs. U, marker pU; +EX and –EX, with and without chloroplast extracts, respectively. (C) Schematic representation of chimeric mRNAs. (D) In vitro editing activity of chimeric mRNAs.