Identification and cloning of the chloroplast gene coding for the large subunit of ribulose-1,5-bisphosphate carboxylase from Chlamydomonas reinhardi

Abstract

mRNA coding for the large subunit (LS) of ribulose-1,5-bisphosphate carboxylase [3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39] from Chlamydomonas reinhardi has been isolated from small polyribosomes immunoadsorbed to column-bound anti-LS antibody. 32P-Labeled LS mRNA was used as a hybridization probe to detect LS genes. The probe hybridized to C. reinhardi chloroplast DNA and at hybridization saturation revealed that there are approximately 75 LS genes per chloroplast. When chloroplast DNA was digested with the restriction endonuclease EcoRI and the fragments were transferred to a nitrocellulose filter, the LS mRNA probe hybridized to a DNA fragment of molecular weight 3.2 X 10(6). This same fragment codes (in part) for 16S and 23S chloroplast rRNAs, which are also coded (in part) by fragments of molecular weights 9.0, 2.3, and 0.4 X 10(6). The restriction fragment containing the LS gene has been cloned in the Escherichia coli plasmid pMB9.