The NTHI SulA ortholog is encoded in a dicistronic operon.

<p>Schematic representation of the genetic context of the classical <i>sulA</i> (from <i>E. coli</i>) and the <i>sulA</i>-related ortholog in NTHI (<b>A</b>). See text for details. In contrast to the monocistronic message produced for the classical <i>sulA</i>, the SulA-related ortholog is produced from a dicistronic operon. RT-PCR was used to validate co-transcription of <i>argR</i> and <i>sulA</i> (<b>B</b>).</p>