Fig. 4.

Modulation of gpps expression via RBS engineering to optimize limonene biosynthesis. (A) A synthetic RBS library with varying translation rates was used to modulate the expression of gpps. (B) GPPS was fused with an enhanced yellow fluorescent protein (EYFP) using a peptide linker to verify the strength of synthetic RBSs. (C) Limonene production in Synechococcus 2973 using the RBS library to express gpps. (D) Fluorescence level of GPPS-EYFP fusion protein expressed by the RBS library. The experiment was conducted in 1% CO₂ and 250 ​μmol photons m⁻² ​s⁻¹ light. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)