attB_BsaI

The attB site is one of the two target sites of tyrosine recombinases (YR) and serine recombinases (SR). These recombinases mediate recombination between two non-identical target sites, attP and attB, each of which contains a short integration core flanked by imperfect inverted repeats. Exchange between the attP/attB pair results in the formation of hybrid sites (attL and attR) that are no longer a substrate of the original integrase, and thus the exchange reaction is irreversible. The relative orientation (direct or inverted), and location of the two target sites define the type of possible modification include deletion of DNA, generation of chromosomal rearrangements, integration of DNA into the genome, and replacement of genetic material with that from a donor plasmid.