Reiteration frequency of the gene coding for the small subunit of ribulose--1,5--bisphosphate carboxylase.

The messenger RNA coding for the precursor of the small subunit of ribulose--1,5--bisphosphate (Ru-P2) carboxylase has been partially purified from pea leaves. The mRNA has a size of 11.5S, is approximately 800 nucleotides long and, on cell-free translation, directs the synthesis of a single major polypeptide of 20,000 daltons. Antiserum for the small subunit of Ru-P2 carboxylase immunoprecipitated 52% of the 35S--methionine-labeled cell-free translation products. The RNA hybridizes with pea DNA with monophasic kinetics corresponding to the presence of one, or very few, gene copies per haploid genome.