Map and DNA sequence of the primary and 15 secondary integration sites for ICE<i>Bs1</i>.

<p><b>A.</b> Approximate position of the primary and 15 secondary ICE<i>Bs1</i> integration sites on the <i>B. subtilis</i> chromosome. The circle represents the <i>B. subtilis</i> chromosome with the origin of replication (<i>oriC</i>) indicated by the black rectangle at the top. The slash marks represent the approximate location of the ICE<i>Bs1</i> insertion site. The name of the gene near which (<i>ygxA</i>) or into which (all other locations) ICE<i>Bs1</i> inserted is indicated on the outside of the circle. The arrows on the inside of the circle indicate the direction of ICE<i>Bs1</i> replication for each insertion. <i>trnS-leu2</i> (in bold) contains the primary ICE<i>Bs1</i> integration site <i>attB</i>. <b>B.</b> DNA sequence of the primary and 15 secondary integration sites. The gene name is indicated on the left, followed by the DNA sequence (chromosomal target). The primary attachment site (<i>attB</i>) is a 17 bp sequence with 5 bp inverted repeats (underlined) separated by a 7 bp spacer. Mismatches from <i>attB</i> are indicated in bold, capital letters. “mm” indicates the number of mismatches from the primary 17 bp <i>attB</i>. “occurrences” indicates the number of independent times an insertion in each site was identified. Percentages of the total (27) are indicated in parenthesis. The * next to <i>yqhG</i> indicates that two different ICE<i>Bs1</i> insertions were isolated in this gene, once in each orientation. <b>C.</b> Sequence logo of the ICE<i>Bs1</i> secondary attachment sites. Using Weblogo 3.3 <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003623#pgen.1003623-Crooks1" target="_blank">[21]</a>, we generated a consensus motif of the 26 bases surrounding the insertion site of the 15 secondary insertion sites for ICE<i>Bs1</i>. For comparison, the primary attachment site for ICE<i>Bs1</i> is a 17 bp region with 5 bp inverted repeats and a 7 bp spacer region in the middle <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003623#pgen.1003623-Lee2" target="_blank">[10]</a>. The size of each nucleotide corresponds to the frequency with which that nucleotide was observed in that position in the secondary attachment sites.