A study of mitochondrial ribosomes from the higher plant Solanum tuberosum L.

Ribosomal subunits are isolated from potato tuber mitochondria devoid of contaminating organelles. The sedimentation constants of the two mitochondrial ribosomal subunits are 33S and 50S respectively. The apparent sizes of the high molecular weight RNAs are 19S and 25S. The proteins of these ribosomes have been analyzed by two-dimensional electrophoresis in SDS polyacrylamide gels to determine their number and molecular weights. The small subunit contains 35 protein species ranging from 8 to 60 kDa. The 50S large subunit contains 33 protein species ranging from 12 to 46 kDa. These preliminary results are the first analysis made on mitochondrial ribosomes from a higher plant.