Cloning and expression of the chloroplast-encoded rbcL and rbcS genes from the marine diatom Cylindrotheca sp. strain N1

Both the rbcL and rbcS genes, encoding the large and small subunits, respectively, of ribulose 1,5-bisphosphate carboxylase/oxygenase, have been found to be encoded by chloroplast DNA in the marine diatom Cylindrotheca sp. N1. The rbcS gene in this diatom was found to be adjacent to the rbcL gene by a combination of: (i) Southern-blotting analyses, using heterologous probes; (ii) examination of recombinant proteins synthesized in Escherichia coli, directed by cloned rbcL/rbcS genes; and (iii) synthesis of enzymatically active heterologous Rubisco protein in vivo by recombinant DNA procedures using large subunits of Anacystis nidulans and small subunits of Cylindrotheca sp. N1. It appears that two copies of rbcL and rbcS genes are encoded by the chloroplast DNA of this diatom.