The TIM-barrel fold: a versatile framework for efficient enzymes

Recent studies on triosephosphate isomerase (TIM)-barrel enzymes highlight the remarkable versatility of the TIM-barrel scaffold. At least 15 distinct enzyme families use this framework to generate the appropriate active site geometry, always at the C-terminal end of the eight parallel beta -strands of the barrel. Sequence and structure comparisons now suggest that many of the TIM-barrel enzymes are evolutionarily related. Common structural properties of TIM-barrel enzymes are discussed. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.