Mutations in ams , hha and a previously unidentified PhoP-activated gene ( pag ) lead to increased hilA expression ( Fahlen et al. , 2000 , 2001 ) .
Mutations in a previously unidentified PhoP-activated gene lead to increased hilA expression .
The response regulator PhoP represses hilA and the prg ( PhoP-repressed genes ) genes ( Pegues et al. , 1995 ; Bajaj et al. , 1996 ) , whereas transcription of PhoP-activated genes ( pag ) required for survival within macrophages is activated ( Miller et al. , 1989 ; Belden and Miller , 1994 ) .