Flexi(R) System

A directional cloning method for protein-coding sequences, Flexi Vector System is based on 2 rare-cutting restriction enzymes, SgfI & PmeI, and provides a rapid, efficient and high-fidelity way to transfer protein-coding regions without resequencing. Flexi Vectors carry the lethal barnase gene, replaced by the DNA fragment of interest to act as a positive selection for successful insert ligation. The system does not require appending multiple amino acids to the amino or carboxy termini of the protein of interest. Nor does it require an archival entry vector; most applications allow direct entry into the vector suited to the experimental design. C-terminal Flexi Vectors allow expression of C-terminal-tagged proteins. While the vectors can act as acceptors of protein-coding regions flanked by SgfI & PmeI, they lack a PmeI site and contain a different blunt-ended site, EcoICRI. This joined sequence cannot be removed from the C-terminal Flexi Vectors and transferred to other Flexi Vectors.