The locations of the SlyA sites within PslyA were consistent with the observed autoregulation of slyA expression .
The region protected by SlyA includes the imperfect palindrome TTTAG-N7-CTTAA , which is similar to the SlyA binding sequence TTAG-N4-CTAA described for the slyA promoter ( 32 ) , the only SlyA-regulated promoter investigated in molecular detail .
The polymyxin B susceptibility of the slyA mutant was the same as that exhibited by the ugtL mutant ( Fig. 5A ) and could be complemented to wild-type levels by a plasmid that expressed the ugtL gene from a heterologous promoter ( Fig. 5B ) , suggesting that ugtL is the only SlyA-regulated gene mediating polymyxin B resistance .
Sensitivity to CAMPs is also regulated by SlyA , a transcriptional regulator ; mutation of slyA renders S. typhimurium highly sensitive to the CAMP polymyxin B .
2 to CAMPs is also regulated by SlyA , a transcriptional regulator ; mutation of slyA renders S. typhimurium highly sensitive to the CAMP polymyxin B .
Although slyA mutants are able to invade deep tissues , they are unable to proliferate efficiently within the reticuloendothelial cells of murine hosts , suggesting that Salmonella strains are unable to withstand host cellular antimicrobial mechanisms in the absence of SlyA-regulated genes .