To understand the function of TdcA in pathogenesis , we performed two-dimensional gel electrophoresis and found that flagellar and PhoP-regulated proteins were affected by the tdcA mutation .
To further investigate the association between tdcA with phoP , we constructed chromosomal lacZ fusion strains of PhoP-regulated ( mgtA and pagD ) and SPI2 genes ( ssaG and sseA ) ( Navarre et al. , 2005 ) .