Lrp is a positive regulator of the expression of type 1 fimbriae in Salmonella through direct interaction with the fimZ promoter region .
Lrp-regulated genes in Salmonella include fimZ , for type 1 fimbria expression ( 67 ) ; ilvIH , for branched amino-acid biosynthesis ( 93 ) ; hisJ , for D-histidine utilization ( 44 ) ; traJ , for conjugal transfer of virulence plasmid pSLT ( 13 ) ; and pef , for pSLT plasmid-encoded fimbriae ( 74 ) .
The Lrp directly binds the fimZ promoter
EMSA was used to test the binding of Lrp at indicated concentrations to 6 ′ - FAM-labeled fimZ promoter .