Stability, catalytic versatility and evolution of the (beta alpha)(8)-barrel fold

The (beta alpha)(8)-barrel is a versatile single-domain protein fold that i s adopted by a large number of enzymes. The (beta alpha)(8)-barrel fold has been used as a model to elucidate the structural basis of protein thermost ability and in studies to interconvert catalytic activities or substrate sp ecificities by rational design or directed evolution. Recently, the (beta a lpha)(4)-half-barrel was identified as a possible structural subdomain.