关键词: 番茄, 醇酰基转移酶, 克隆, 原核表达, 酯类合成

Abstract: Volatile esters are important aromatic compounds accumulated in many ripe fruits. Alcohol acyltransferase (AAT) plays a key role in the formation of volatile esters. In the present study, a full-length cDNA sequence homologous with other plant AAT genes was isolated by RT-PCR from tomato ripe fruit, and named as SlAAT1(GenBank Accession No.JN398667). Results of sequence analyses showed SlAAT1 encodes a 442-amino acid protein, which exhibits conserved features of the BAHD family of acetyl transferase, such as HxxxD and DFGWG motifs. Phylogenetic analysis revealed that SlAAT1 is very closely related to the apple MpAAT1, Clarkia breweri BEBT, and tobacco Hsr201. The recombinant plasmid was transformed into E. coil BL21 (DE3) to express the SlAAT1-His6 protein in the optimized condition (22℃, 0.8 mmol·L^-1 IPTG). The purified recombinant SlAAT1 protein was shown to have acetyltransferase activity, suggesting its role in volatile ester formation.

Key words: Alcohol acyltransferase, cloning, prokaryotic expression, ester formation