Our laboratory is interested in the structure and function of the ribosome, the large protein-RNA complex that synthesizes proteins using genetic instructions encoded in the mRNA template. Following the determination of the 30S subunit and its complexes with antibiotics and ligands in 2000, and the entire 70S ribosome with mRNA and tRNA ligands in 2006, we have determined high-resolution structures of many functional states of the ribosome. These structures have shed light on the role of the ribosome in decoding of mRNA, peptidyl transfer, translocation, and termination. We have also elucidated complexes of the ribosome involved in stress response and quality control, and the structures of mitochondrial ribosomes.