Optimizing E. coli-Based Membrane Protein Production Using Lemo21(DE3) or pReX and GFP-Fusions.

Optimizing the conditions for the production of membrane proteins in E. coli is usually a laborious and time-consuming process. Combining the Lemo21(DE3) strain or the pReX T7-based expression vector with membrane proteins C-terminally fused to Green Fluorescent Protein (GFP) greatly facilitates the optimization of membrane protein production yields. Both Lemo21(DE3) and pReX allow precise regulation of expression intensities of genes encoding membrane proteins, which is critical to identify the optimal production condition for a membrane protein. The use of GFP-fusions allows direct monitoring and visualization of membrane proteins at any stage during the production optimization process.