Domain analysis and engineering of multifunctional β-carotene synthase, CrtIBY, for lycopene and phytoene production.

The multifunctional β-carotene synthase, CrtIBY, derived from Aurantiochytrium sp. KH105 catalyzes to produce β-carotene from geranylgeranyl diphosphate through three serial enzymatic reactions with a trace amount of intermediates such as phytoene and lycopene. In this research, the functions of domains of CrtIBY were studied and the product specificity was modified by protein engineering techniques including the removal of functional motif and site-directed mutagenesis. Saccharomyces cerevisiae transformants expressing the functionally modified CrtIBY mutants accumulated phytoene and lycopene. These mutants are expected to be useful to supply raw materials of pharmaceuticals, cosmetics, and health foods.