Interactions between DNA, transcriptional regulator Dreb2a and the Med25 mediator subunit from Arabidopsis thaliana involve conformational changes
2012 (English)In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 40, no 13, 5938-5950 p.Article in journal (Refereed) Published
Mediator is a multiprotein coregulatory complex that conveys signals from DNA-bound transcriptional regulators to the RNA polymerase II transcription machinery in eukaryotes. The molecular mechanisms for how these signals are transmitted are still elusive. By using purified transcription factor Dreb2a, mediator subunit Med25 from Arabidopsis thaliana, and a combination of biochemical and biophysical methods, we show that binding of Dreb2a to its canonical DNA sequence leads to an increase in secondary structure of the transcription factor. Similarly, interaction between the Dreb2a and Med25 in the absence of DNA results in conformational changes. However, the presence of the canonical Dreb2a DNA-binding site reduces the affinity between Dreb2a and Med25. We conclude that transcription regulation is facilitated by small but distinct changes in energetic and structural parameters of the involved proteins.
Place, publisher, year, edition, pages
Oxford: Oxford University Press, 2012. Vol. 40, no 13, 5938-5950 p.
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:umu:diva-54407DOI: 10.1093/nar/gks265ISI: 000306970700019PubMedID: 22447446OAI: oai:DiVA.org:umu-54407DiVA: diva2:523731