Skip to main content
. Author manuscript; available in PMC: 2014 Jul 15.
Published in final edited form as: Methods Cell Biol. 2011;104:195–208. doi: 10.1016/B978-0-12-374814-0.00011-2

Figure 1.

Figure 1

Mechanism of phiC31 integrase action. A) The integrase of the phiC31 Streptomyces bacteriophage (Int) catalyzes recombination between an attachment site in the phage genome (attP) and a site in the bacterial genome (attB). In eukaryotic applications, it has generally been found that recombination is more efficient when the attP site is provided by the host genome rather than by the donor plasmid. B) Generalized strategy for use of phic31 integrase (Int) for transgene excision. PhiC31 integrase (Int) can catalyze recombination between att sites in the same molecule; if these sites are in the same orientation the intervening sequenced will be excised. In this way, the integrase can be be used to inactivate a gene (gene1) and/or activate a second gene (gene2) in a tissue-restricted and/or temporally-regulated manner.