Quantitative mass spectrometry analysis of 70S ribosomes from iSAT

The ribosome is one of the largest and the most complicated enzymes in cells, making up 25% of the bacterial cell’s dry mass, and is responsible for protein synthesis in all organisms on earth. In 2013, Jewett et al. reported an in vitro system named integrated rRNA synthesis, ribosome assembly, and translation (iSAT) reaction, which provided a defined system for ribosome biogenesis in a near-physiological environment.In this project, the r-protein composition in 30S and 50S ribosomeal subunits assembled in the iSAT reaction was quantified by mass spectrometry compared to 15N labeled 70S ribosomes.