Rhizobium meliloti와 R. leguminosarum의 dctA 프로모터에서 DctD 및 NtrC가 중재된 in vitro 전사활성

The gene product of dctD (DctD) activates transcription from the dctA promoter regulatory region by the s54-holoenzyme form of RNA polymerase (Es54) in Rhizobium meliloti and R. leguminosarum. The Escherichia coli integration host factor (IHF) stimulated DctD-mediated activation from the dctA promoter regulatory region of R. leguminosarum but not R. meliloti. In the absence of UAS, IHF inhibited DctD-mediated activation from both of these promoter regulatory regions. IHF also inhibited activation from R. leguminosarum dctA by nitrogen regulatory protein C (NtrC), another activator of Es54 but not by one which lacks a specific binding site in this promoter regulatory region. IHF, however, stimulated NtrC-mediated activation from the R. meliloti dctA promoter. Upon removal of the UAS, IHF inhibited NtrC-mediated transcription activation from the R. meliloti dctA promoter regulatory region. These data suggest that IHF likely faciliates productive contacts between the activators NtrC or DctD and Es54 to stimulate activation from dctA promoter. KCI Citation Count: 0