Reverse transcriptase (RT-) PCR on total <i>S. aureus</i> RNA. RT-PCR was carried out to evaluate whether the open reading frames of the <i>S. aureus</i> vitamin B1 metabolism are clustered and thereby suggested to be organized in operons.

<p>(A) Amplification of the cluster consisting of the ORFs <i>gtpase</i>, <i>epi</i> and <i>tpk</i> using the primers <i>Sa</i>GTPase-IBA3-S and <i>Sa</i>TPK-IBA3-AS (lane 2); as controls, the PCR was either carried out without RT step (lane 1) or amplification of the flanking ORFs was performed with the primers <i>Sa</i>GTPase-IBA3-S and <i>Sa</i>GTPase-IBA3-AS (lane 3) and <i>Sa</i>TPK-IBA3-S and <i>Sa</i>TPK-IBA3-AS (lane 4). The ORFs of the operon consisting of <i>tenA</i>, <i>thiM</i>, <i>thiD</i> and <i>thiE</i> were amplified using the primers <i>Sa</i>TenA-IBA3-S and <i>Sa</i>ThiE-IBA3-AS (lane 6). As controls the PCR was carried out without RT step (lane 5) and amplification of the flanking open reading frames was performed either with the primer <i>Sa</i>TenA-IBA3-S and <i>Sa</i>TenA-IBA3-AS (lane 7) or the primer <i>Sa</i>ThiE-IBA3-S and <i>Sa</i>ThiE-IBA3-AS (lane 8). (B) The organisation of the proposed operons is schematically illustrated. Note: Numbering of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007656#pone-0007656-g001" target="_blank">figure 1B</a> refers to the respective lane number of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007656#pone-0007656-g001" target="_blank">figure 1A</a>.