Ada E. Yonath (Hebrew: עדה יונת‎, pronounced [ˈada joˈnat]) (born 22 June 1939) is an Israeli crystallographer best known for her pioneering work on the structure of the ribosome. She is the current director of the Helen and Milton A. Kimmelman Center for Biomolecular Structure and Assembly of the Weizmann Institute of Science. In 2009, she received the Nobel Prize in Chemistry along with Venkatraman Ramakrishnan and Thomas A.