Vector map of plasmid pMTL-YZ14.

<p>Expression of the hyperactive <i>mariner</i> transposase gene <i>Himar1 C9</i> was driven by the <i>C</i>. <i>difficile</i> toxin B promoter, P_tcdB. The plasmid backbone consisted of the conditional replicon between restriction sites AscI and FseI, the macrolide-lincosamide-streptogramin B antibiotic resistance gene <i>ermB</i>, and the Gram-negative replicon, ColE1. The whole mariner element (i.e., transposase gene and <i>catP</i> mini-transposon) can be excised as a SbfI fragment. The control plasmid pMTL-YZ13 was identical, except that the Gram-positive replicon is the pCB102 replicon from <i>C</i>. <i>butyricum</i>. This plasmid conforms to the pMTL80000 modular system for <i>Clostridium</i> shuttle plasmids [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0122411#pone.0122411.ref032" target="_blank">32</a>].