The novel Fh8 fusion technology for protein expression in Escherichia coli: a comparison with the traditionally used fusion systems

Abstract

[Excerpt] The recombinant expression of natural proteins in Escherichia coli is limited by the lack of efficient methods for soluble production. Several efforts have been made to overcome this limitation, including the genetic fusion of highly soluble protein domains (fusion partners) to the target proteins. Among the available fusion partners, the E. coli maltose-binding protein (MBP), glutathione S-transferase (GST) and N-utilization substance A (NusA) are often used to enhance protein solubility. However, due to their large size, these partners can be problematic for structural and functional analyses, requiring their removal using specific proteases. The removal of the fusion partner is not always successful and the resulting cleaved target protein may also precipitate into insoluble aggregates.