FLP recombinase catalyzes the site-specific recombination of DNA between FRT sites. It has been widely used for generating conditional knockout mice, mediated by FLP/FRT system.

Recombinant cell-permeant FLP recombinase Tat-Flp was purified from an HEK293 cell line overexpressing FLP Recombinase from yeast Saccharomyces cerevisiae with additional N-terminal 6XHis tag, a Tat peptide (GRKKRRQRRRPPAGTSVSL) and an NLS sequence (PKKKRKV). In addition, this \"thermostable\" mutant FLP (P2S L33S Y108N S294P) has ~ 4-10 fold higher activity than wild-type FLP at 37°C.

Addition of 100 units of Tat-Flp to FRT-RFP-Stop-FRT-GFP 293T reporter cells resulted in 60~90% recombination efficiency.

Figure 1: Tat-Flp transduction efficiency is concentration dependent.

1: no Tat-FLP; 2~8: adding 5, 10, 25, 50, 75, 100 and 200 units of Tat-FLP to HEK 293T cells transfected with FRT-RFP-Stop-FRT-GFP plasmid DNA. Pictures were taken 4 days after transduction with various amount of Tat-FLP