Cloning and functional characterization of the geranylgeranyl diphosphate synthase(GGPPS)from Elizabethkingia meningoseptica sp.F2.

To date, there is no functional characterization of Em GGPPS (from Elizabethkingia meningoseptica sp.F2) as enzymes catalyzing GGPP. In this research, maltose-binding protein (MBP), disulfide bond A (DbsA), disulfide bond C (DbsC), and two other small protein tags, GB1 (Protein G B1 domain) and ZZ (Protein A IgG ZZ repeat domain), were used as fusion partners to construct an Em GGPPS fusion expression system. The results indicated that the expression of MBP- Em GGPPS was higher than that of the other four fusion proteins in E. coli BL21 (DE3). Additionally, using Em GGPPS as a catalyst for the production of GGPP was verified using a color complementation assay in Escherichia coli. In parallel with it, the enzyme activity experiment in vitro showed that the Em GGPPS protein could produce GGPP, GPP and FPP. Finally, we successfully demonstrated MK-4 production in engineered E. coli by overexpression of Em GGPPS. • Fusion expression of five tags (GB1, ZZ, MBP, DbsA, DbsC) with GGPPS was evaluated in two different E.coli strains. • Em GGPPS has been confirmed produces GPP, FPP and GGPP in vivo and in vitro assays. • The menaquinone-4 (MK-4) were first synthesized in E. coli under anaerobic conditions. [ABSTRACT FROM AUTHOR]