Cooperative Action of the Catabolite Activator Protein and AraC In Vitro at the araFGH Promoter
AUTOR(ES)
Johnson, Casonya M.
FONTE
American Society for Microbiology
RESUMO
Full activation of transcription of the araFGH promoter, pFGH, requires both the catabolite activator protein (CAP) and AraC protein. At pFGH, the binding site for CAP is centered at position −41.5, an essential binding site for AraC is centered at position −79.5, and a second, nonessential binding site is centered at position −154.5. In this work, we used the minimal promoter region required for in vivo activation of pFGH to examine the roles of CAP and AraC in stimulating formation of open complexes at pFGH. Migration retardation assays of open complexes showed that RNA polymerase binds exceptionally tightly to the AraC-CAP-pFGH complex and that the order of addition of proteins to the initiating complex is important. Similar assays with RNA polymerase containing truncated alpha subunits suggest that AraC interacts with the C-terminal domain of the alpha subunit. Finally, AraC protein also acts to prevent the improper binding of RNA polymerase at a pseudo promoter near the true pFGH promoter.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=101909Documentos Relacionados
- Sequence elements in the Escherichia coli araFGH promoter.
- In Vitro Activation of the Transcription of araBAD Operon by araC Activator
- Mutations in the araC regulatory gene of Escherichia coli B/r that affect repressor and activator functions of AraC protein.
- Arabinose-induced binding of AraC protein to araI2 activates the araBAD operon promoter.
- Purification of the araC Protein
