A hyperthermostable bacterial histone-like protein as an efficient mediator for transfection of eukaryotic cells

Gene delivery has shown potential in a variety of applications, including basic research, therapies for inborn genetic defects, cancer, AIDS, tissue engineering(1,2), and vaccination(3). Most available systems have serious drawbacks, such as safety hazards(4), inefficiency under in vivo-like conditions, and expensive production. When using naked DNA(2,5), for instance, a large amount of ultrapure DNA has to be applied as a result of degradation by nucleases(6). Similarly, the use of eukaryotic histones(7,8), synthetic peptides, or peptide nucleic acids(9,10) may be limited by high production costs. We have demonstrated a biotechnologically feasible and economical approach for gene delivery using the histone-like protein from the hyperthermostable eubacterium Thermotoga maritima, TmHU11,12 as an efficient gene transfer reagent. HU can be easily isolated from recombinant Escherichia coli, is extraordinarily stable, and protects dsDNA from thermal denaturation(12). This study demonstrates its use as an inexpensive tool for gene delivery.