Figure 1.

Directed evolution of RecHTLV

(A) Alignment of the loxHTLV (RecHTLV) target sequence to loxP (Cre), loxLTR (Tre), and loxBTR (Brec1). Mismatches to the loxP sequence are marked in red and asymmetries within the sequences are underlined. The spacers are shown in gray. (B) Scheme of the RecHTLV evolution process. The activity of the recombinase libraries from the first and last cycle in each subsite are shown as images of the agarose gels, where the upper bands correspond to the non-recombined plasmids and are illustrated with two triangles. The smaller faster migrating bands indicate recombined plasmids (shown here as one triangle). The number of evolution cycles performed in each subsite is marked between the two agarose gels. The triangles below indicate the reduction of L-arabinose (L-ara) levels during evolution for each target site.