Construction of the single deletion mutants of the genes <i>sll0923</i>, <i>sll1581</i>, <i>sll5052</i> and <i>slr1875</i>.

<p>(<b>A</b>) Schematic representation of the studied chromosome loci in the wild-type (WT) strain and the mutants <i>Δsll0923</i>::Km^r, <i>Δsll5052</i>::Sp^r, <i>Δslr1875</i>::Km^r and <i>Δsll1581</i>::Km^r constructed in this study. The studied genes are represented by boxes, which point into the direction of their transcription. The PCR primers used to verify the presence (in the WT strain) and absence (in the deletion mutant) of the studied genes are represented by the small grey triangles. The size of corresponding PCR products, which are represented by the double arrows, are indicated in kilobases (kb). (<b>B</b>) Typical UV-light images of the agarose gels showing the PCR products corresponding to the WT and mutant chromosomes. These data show that all deletion mutants harbour no WT copy of the chromosome.