Mutants identified in the MudJ transposon mutagenesis screen Tn insertion site Description Strain PM sensitive imp/surA tolB gnd gnd yibD dgoA pmrC pmrC pmrC pmrC pmrI pmrI 851 895 JSG JSG JSG JSG JSG JSG JSG JSG JSG JSG JSG JSG 1272-1290-897-899 901-918-973-1036 923 925 PmrA regulated PmrA regulated , PM sensitive PmrA-regulated genes identified in the screen in iron resistance , JSG897 ( yibD ) and JSG899 ( dgoA ) were grown on solid N-minimal-medium supplemented with 100 M FeSO4 .
yibD , dgoA , and gnd ( likely affecting pmrE ) played no role in PmrA-regulated resistance to high iron concentrations , while surA and tolB mutations grew poorly on high iron media .
gnd is the final gene in the rfb locus involved in LPS biosynthesis ( 34 ) and is located upstream of pmrE , a PmrA-regulated gene shown to be necessary for PM resistance and wild-type virulence ( 17 ) .