CHARACTERIZATION OF THE GENE AND MESSENGER-RNA OF THE LARGE SUBUNIT OF RIBULOSE 1,5-DIPHOSPHATE CARBOXYLASE IN CHLAMYDOMONAS-REINHARDII

The gene coding for the large subunit of ribulose 1,5-diphosphate carboxylase (LS) of Chlamydomonas reinhardii has been cloned and localized at a unique site on the physical map of the chloroplast genome. It is contained within a 5.5 × 103 base EcoRI fragment which can act as template in vitro in a coupled transcription-translation system to produce a polypeptide, of the same size as LS, which is specifically immunoprecipitated with antibodies prepared against LS. The fingerprint of this in vitro synthesized polypeptide closely resembles that of cellular LS. The hybrid plasmid coding for LS inhibits specifically the in vitro translation of LS when it is hybridized to poly(A)- RNA prior to translation. The size of the LS messenger RNA has been estimated at 1.2 ± 0.3 × 103 bases by measuring R-loop structures in the electron microscope and two major species at 1.5 × 103 and 2.5 × 103 bases have been detected by hybridizing labelled LS-plasmid to cellular RNA fractionated on denaturing agarose gels. © 1979.