Engineering expression and function of membrane proteins.

Membrane proteins are involved in a diverse array of cellular functions and part of many important metabolic pathways. As such, they are attractive targets in the pharmaceutical and bio-based chemical industries. Despite their great potential, many challenges remain before membrane proteins gain widespread success in biotechnology. The two biggest issues are that expression of membrane proteins leads to inhibition of cellular growth and metabolism, and native membrane proteins often lack a desired function or specificity for use in engineered processes. To address these issues, protein engineering and synthetic biology approaches are leading the charge to develop membrane proteins for biotechnological applications. Here, we describe current methods for engineering membrane proteins and optimizing their expression levels in bacteria. We highlight success stories and describe challenges that still face this growing field.