ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
The transcriptional activator, MarA, interacts with RNA polymerase (RNAP) to activate promoters of the mar regulon. Here, we identify the interacting surfaces of MarA and of the carboxy-terminal domain of the α subunit of RNAP (α-CTD) by NMR-based chemical shift mapping. Spectral changes were monitored for a MarA-DNA complex upon titration with α-CTD, and for α-CTD upon titration with MarA-DNA. The mapping results were confirmed by mutational studies and retention chromatography. A model of the ternary complex shows that α-CTD uses a ‘265-like determinant’ to contact MarA at a surface distant from the DNA. This is unlike the interaction of α-CTD with the CRP or Fis activators where the ‘265 determinant’ contacts DNA while another surface of the same α-CTD molecule contacts the activator. These results reveal a new versatility for α-CTD in transcriptional activation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2958.2004.04250.x
Permalink