Download MendeleyStructural analysis and DNA binding of the HMG domains of the human mitochondrial transcription factor A
Gangelhoff, T.A., Mungalachetty, P.S., Nix, J.C., Churchill, M.E.(2009) Nucleic Acids Res 37: 3153-3164
- PubMed: 19304746
- DOI: https://doi.org/10.1093/nar/gkp157
- Primary Citation of Related Structures:
3FGH - PubMed Abstract:
The mitochondrial transcription factor A (mtTFA) is central to assembly and initiation of the mitochondrial transcription complex. Human mtTFA (h-mtTFA) is a dual high mobility group box (HMGB) protein that binds site-specifically to the mitochondrial genome and demarcates the promoters for recruitment of h-mtTFB1, h-mtTFB2 and the mitochondrial RNA polymerase. The stoichiometry of h-mtTFA was found to be a monomer in the absence of DNA, whereas it formed a dimer in the complex with the light strand promoter (LSP) DNA. Each of the HMG boxes and the C-terminal tail were evaluated for their ability to bind to the LSP DNA. Removal of the C-terminal tail only slightly decreased nonsequence specific DNA binding, and box A, but not box B, was capable of binding to the LSP DNA. The X-ray crystal structure of h-mtTFA box B, at 1.35 A resolution, revealed the features of a noncanonical HMG box. Interactions of box B with other regions of h-mtTFA were observed. Together, these results provide an explanation for the unusual DNA-binding properties of box B and suggest possible roles for this domain in transcription complex assembly.
Organizational Affiliation:
Department of Pharmacology, University of Colorado Denver, School of Medicine, 12801 East 17th Avenue, Aurora, CO 80045-0511, USA.
