Americans Venkatraman Ramakrishnan and Thomas Steitz and Israeli Ada Yonath won for atom-by-atom mapping of the protein-making factories within cells. Their efforts have helped researchers develop antibiotics. Americans Venkatraman Ramakrishnan and Thomas Steitz and Israeli Ada Yonath won the 2009 Nobel Prize in chemistry today for atom-by-atom mapping of the protein-making factories within cells.