DNA sequence of <i>att</i> and p<i>attP</i> sites.

<p>A) Wild type <i>attP</i> and <i>attB</i> sites. After recombination two hybrids sites are formed: <i>attL</i> and <i>attR</i>. B) Recombination between <i>attB</i> site and the human locus Xq22.1 This recombination generates a p<i>attR</i> which has been isolated by inverse PCR. Xq22.1 had been described previously as a human p<i>attP</i> by MP Calos et al., who isolated the same p<i>attR</i>.