The first of its kind, this volume presents the latest research findings on the chaperonins, the best studied family of a class of proteins known as molecular chaperones. These findings are changing our view of some fundamental cellular processes involving proteins, especially how proteins fold into their functional conformations. - Origins of the new view of protein folding - Prokaryotic chaperonins - Eukaryotic chaperonins - Evolution of the chaperonins - Refolding of denatured proteins - Organelle biosynthesis - Biomedical aspects