Fig. 6.

Transcript mapping of the S. marcescens Db10 type VI secretion system gene cluster. (A) Schematic diagram of the T6SS genomic context showing intergenic regions 1 to 17 analyzed. Conserved T6SS genes, including the core TssA-M components indicated by letter, are shaded gray, and the SMA gene numbers are given below. The black arrow indicates the extent of the transcript/operon. (B) RT-PCR detection of transcriptional readthrough of selected intergenic regions (see text). For each amplified region, three PCRs were performed: +RT PCR on cDNA, −RT negative control with no reverse transcriptase, and gDNA positive control on genomic DNA. The experiment was repeated on an independent RNA sample with an essentially identical outcome.