Expression of cloned chloroplast DNA from Euglena gracilis in an in vitro DNA-dependent transcription-translation system prepared from E. coli

Abstract

Recombinant plasmids containing restriction endonuclease fragments of chloroplast DNA from the alga Euglena gracilis were expressed in an in vitro DNA-dependent transcription-translation system prepared from E. coli. The polypeptides synthesized in this system were radioactively labeled and analyzed by SDS-polyacrylamide gel electrophoresis. Expression of chloroplast DNA fragments cloned in both orientations relative to the plasmid vector and of plasmids containing chloroplast DNA fragments whose nucleotide sequences partially overlap one another permitted the identification of 14 different regions on this organellar genome that have the potential to code for polypeptides.