TY - JOUR ID - 2033 TI - Serine carboxypeptidase-like acyltransferases JO - Phytochemistry PY - 2004 SP - 517-524 AU - Milkowski, C. AU - Strack, D. AU - VL - 65 UR - DO - 10.1016/j.phytochem.2003.12.018 AB - In plant secondary metabolism, an alternative pathway of ester formation is facilitated by acyltransferases accepting 1-O-β-acetal esters (1-O-β-glucose esters) as acyl donors instead of coenzyme A thioesters. Molecular data indicate homology of these transferases with hydrolases of the serine carboxypeptidase type defining them as serine carboxypeptidase-like (SCPL) acyltransferases. During evolution, they apparently have been recruited from serine carboxypeptidases and adapted to take over acyl transfer function. SCPL acyltransferases belong to the highly divergent class of α/β hydrolases. These enzymes make use of a catalytic triad formed by a nucleophile, an acid and histidine acting as a charge relay system for the nucleophilic attack on amide or ester bonds. In analogy to SCPL acyltransferases, bacterial thioesterase domains are known which favour transferase activity over hydrolysis. Structure elucidation reveals water exclusion and a distortion of the oxyanion hole responsible for the changed activity. In plants, SCPL proteins form a large family. By sequence comparison, a distinguished number of Arabidopsis SCPL proteins cluster with proven SCPL acyltransferases. This indicates the occurrence of a large number of SCPL proteins co-opted to catalyse acyltransfer reactions. SCPL acyltransferases are ideal systems to investigate principles of functional adaptation and molecular evolution of plant genes.Serine carboxypeptidase-like (SCPL) acyltransferases are involved in the formation of esters, accepting 1-O-β-glucose esters as acyl donors. SCPL proteins make use of a catalytic triad formed by a nucleophile, an acid and histidine acting as a charge relay system for the nucleophilic attack on amide or ester bonds. During evolution, these enzymes apparently have been recruited from serine carboxypeptidases and adapted to take over acyl transfer instead of hydrolysis functions. By sequence comparison, a distinguished number of Arabidopsis SCPL proteins cluster with proven SCPL acyltransferases. These enzymes might be ideal systems to investigate principles of functional adaptation and molecular evolution of plant genes. A2 - C1 - Cell and Metabolic Biology ER -