STOCKHOLM (AFP) - Venkatraman Ramakrishnan and Thomas Steitz of the US and Israel's Ada Yonath on Wednesday won the Nobel Chemistry Prize for their studies on the ribosome.

The trio were honoured for "mapping the ribosome -- one of the cell's most complex machineries -- at the atomic level," it said.

Ribosomes produce proteins, which in turn control the chemistry of all living organisms. They are crucial to life, and are also a major target for new antibiotics.