Abstract:
Tea is one of the most popular beverages worldwide, native to Southeast Asia but currently cultivated in over 35
countries. Studies on its chemical composition reveal that polyphenol metabolites account for 25% to 35% of the
total dry weight. Tea has many health benefits owing to secondary metabolites whose level of expression in
various tea clones determine tea flavor. The flavor (taste and aroma) and the color of processed tea are used to
assess its quality and therefore a detailed analysis of key enzymes involved in the synthesis of secondary
metabolites is necessary. This study employed a computational approach in the analysis of these enzymes to gain
insight into the mechanism of synthesis of these bioactive secondary metabolites. Biological databases were used
to retrieve amino acid sequences of these key enzymes. Consensus conserved regions in these sequences were
identified from highly identical homologs which were useful in modeling the enzymes' three dimensional
structures. A total of 14 key enzymes were analyzed and pockets and cavities in their structures; hence the
putative substrate binding sites determined, which gave insight into the enzymes-substrate as well as enzyme
cofactor interactions. The preferred orientations of the interactions between substrates and/or co-factors with the
enzymes were also simulated through molecular docking. Analysis of these enzymes revealed unique enzyme
structures and very specific substrate and co-factor preference. This analysis offers a platform for optimization of
selective expression of these key enzymes through gene expression assays that can potentially alter the quality
yield of tea clones.
