Structure, evolution and action of vitamin B6-dependent enzymes

Abstract

The number of known three-dimensional structures of vitamin B6-dependent enzymes has doubled in the past two years. A fourth type of fold for B6-dependent enzymes, involving a TIM-barrel domain, has been discovered. Alanine racemase is the first known representative of this new fold. Significant progress has been made in understanding the allosteric effects in the tryptophan synthase reaction.