## 2 Results and Discussion
### Genes of a Putative TCS Are Significantly Downregulated by SK-03-92 Treatment  
A surprising microarray result that was no known _S. aureus_ global regulatory genes were shown to be affected by the drug treatment. Microarray analysis of daptomycin treated _S. aureus_ demonstrated that the the _icaR_ gene was dysregulated compared to untreated cells [34]. Our microarray showed that a _tetR_-family transcriptional regulator, SACOL2340, and two genes that comprise a putative TCS in _S. aureus_ annotated as _MW2284_ (14.1-fold downregulated) and _MW2285_ in strain MW2 (26.3-fold downregulated) were downregulated. A bioinformatic analysis of the putative MW2284 and MW2285 \begin{table}
\begin{tabular}{l c l} \hline
**Locus** & **Fold-Difference** & **Description** \\ \hline Lipid Metabolism & & \\ \hline SACOL2091 & \(-\)2.5 & beta-hydroxyacyl-dehydratase FabZ (_fabZ_) \\ SACOL2459 & \(-\)3.8 & para-nitrobenzyl esterase (_phthA_) \\ SACOL1142 & 10.0 & aerobic glycerol-3-phosphate dehydrogenase (_glpD_) \\ \hline Catabolism & & \\ \hline SACOL0135 & \(-\)2.4 & alcohol dehydrogenase, iron-containing (_ddkE_) \\ SACOL0660 & \(-\)3.4 & alcohol dehydrogenase, zinc-containing (_ddkA_) \\ SACOL1158 & \(-\)2.5 & succinate dehydrogenase, cytochrome b558 subunit (_sdkC_) \\ SACOL1604 & \(-\)2.1 & glucokinase (_glk_) \\ SACOL2338 & \(-\)3.5 & hypothetical protein (putative oxidoreductase) \\ SACOL1713 & 2.3 & hypothetical protein, putative ammonia monooxygenase \\ \hline Unknown & & \\ \hline SACOL0089 & \(-\)4.4 & myosin-reactive antigen, 67 kDa \\ SACOL2315 & \(-\)3.8 & conserved hypothetical protein \\ SACOL2338 & \(-\)3.4 & conserved hypothetical protein \\ SACOL2491 & \(-\)2.9 & conserved hypothetical protein \\ SACOL0742 & 3.1 & conserved hypothetical protein \\ SACOL1789 & 2.4 & conserved hypothetical protein \\ \hline \end{tabular}
\end{table} 
Table 2: _Cont._proteins suggest that they comprise a putative two-component regulatory system where MW2284 (LytTR superfamily regulator protein) is the response regulator protein and MW2285 (membrane protein) is the sensor kinase protein. MW2284 was identified as a 440-bp ORF encoding a putative 14.7-kDa transcriptional regulator protein and MW2285 was identified as a 455-bp ORF encoding a putative 15.1-kDa histidine kinase sensor protein. The _MW2285_ ORF has a 3-bp overlap with the _MW2284_ ORF. BLASTP, PSI-BLAST, and BLASTN bioinformatics analyses [65] showed that MW2284 aligned with other two-component regulatory system regulator proteins and MW2285 aligned with other two-component regulatory system sensor proteins. Both proteins have homology with LytTR superfamily proteins involved in the regulation of bacterial genes [66]. LytTR proteins regulate virulence gene expression in a variety of bacterial species including _S. aureus_. The AgrA transcriptional regulator is one of these LytTR-type proteins [67]. Moreover, the _MW2284_ and _MW2285_ ORFs appeared to be conserved across a wide number of Gram-positive species, including all _Staphylococcus_ and _Streptococcus_ species, as well as _Bacillus_, _Clostridium_, _Lactobacillus_, _Listeria_, and _Leuconostoc_. The same LytTR TCS dysregulated in SK-03-92-treated _S. aureus_ was upregulated in purine synthesis deficient mutants in _S. aureus_[68]. The putative sensor kinase (MW2285) was upregulated in _purH_ mutants and the response regulator (MW2284) was upregulated in _purA_ mutants (adenylosuccinate synthetase involved in purine biosynthesis). The response regulator component transcript was also upregulated during anaerobic growth in another study [69]. A transposon mutant of the sensor kinase component has been previously shown to be viable, capable of producing a more robust biofilm, and had a lower LD50 than the parent strain [70; 71]. The mechanistic link between defects in purine synthesis, persister formation, and the LytTR regulatory system remains unclear. Furthermore, RNAseq analysis of resveratrol treated _S.