Abstract
In the presence of the S polypeptide, maize chloroplast DNA-dependent RNA polymerase preferentially transcribes sequences within the 2200-nucleotide-pair-long maize chloroplast chromosome fragment Eco [unk] from a supercoiled chimeric plasmid cloned in Escherichia coli [Jolly, S. O. & Bogorad, L. (1980) Proc. Natl. Acad. Sci. USA 77, 822-826]. Eco [unk] contains one gene for tRNA(His) and one for a 1.6-kilobase RNA that includes an open reading frame. These two genes overlap by at least a few nucleotides and are transcribed divergently from complementary DNA strands. This indicates possible transcriptional regulation of chloroplast DNA at the nucleotide level. The 5' end of tRNA(His) (G-U-G) isolated from maize chloroplasts is indistinguishable from that of the transcript produced from Eco [unk] in vitro by maize chloroplast DNA-dependent RNA polymerase. This purified system initiates RNA synthesis faithfully and exhibits preference for some chloroplast genes. Maize chloroplast DNA for tRNA(His) lacks the sequence C-C-A at its 3' terminus; it is presumably added post-transcriptionally. Maize tRNA(His) has both prokaryotic and eukaryotic features.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.