Salmonella typhimurium encodes an SdiA homolog, a putative quorum sensor of the LuxR family, that regulates genes on the virulence plasmid

The Salmonella typhimurium SdiA homolog was cloned and a systematic screen was implemented on the sdiA-controlled genes. Findings from the analysis of the sequencing of a 4.4-kb fragment, which encodes the S. typhimurium sdiA gene, revealed that the fragment encodes the 5' end UvrC, all of SdiA and SirA and the 3' end of YecC. The S. typhimurium sdiA gene was also found to weakly support the E. coli sdiA gene for suppression of filamentation and for activation of ftsQAZ at promoter 2 due to an ftsZ(Ts) allele.