Organization of the human mitochondrial transcription initiation complex

Details

• Alternative Title:
  Nucleic Acids Res
• Personal Author:
  Yakubovskaya, Elena ; Guja, Kip E. ; Eng, Edward T. ; Choi, Woo Suk ; Mejia, Edison ; Beglov, Dmitri ; Lukin, Mark ; Kozakov, Dima ; Garcia-Diaz, Miguel
• Description:
  Initiation of transcription in human mitochondria involves two factors, TFAM and TFB2M, in addition to the mitochondrial RNA polymerase, POLRMT. We have investigated the organization of the human mitochondrial transcription initiation complex on the light-strand promoter (LSP) through solution X-ray scattering, electron microscopy (EM) and biochemical studies. Our EM results demonstrate a compact organization of the initiation complex, suggesting that protein-protein interactions might help mediate initiation. We demonstrate that, in the absence of DNA, only POLRMT and TFAM form a stable interaction, albeit one with low affinity. This is consistent with the expected transient nature of the interactions necessary for initiation and implies that the promoter DNA acts as a scaffold that enables formation of the full initiation complex. Docking of known crystal structures into our EM maps results in a model for transcriptional initiation that strongly correlates with new and existing biochemical observations. Our results reveal the organization of TFAM, POLRMT and TFB2M around the LSP and represent the first structural characterization of the entire mitochondrial transcriptional initiation complex.
• Subjects:
  DNA-Binding Proteins DNA-Directed RNA Polymerases Humans Methyltransferases Mitochondria Mitochondrial Proteins Models, Molecular Promoter Regions, Genetic Structural Biology Transcription Factors Transcription Initiation, Genetic

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• Source:
  Nucleic Acids Res. 2014; 42(6):4100-4112.
• Pubmed ID:
  24413562
• Pubmed Central ID:
  PMC3973321
• Document Type:
  Journal Article
• Funding:
  C06 RR017528-01-CEM/CE/NCIPC CDC HHS/United States ; F30 ES022930/ES/NIEHS NIH HHS/United States ; F30-ES022930/ES/NIEHS NIH HHS/United States ; R00-ES015421/ES/NIEHS NIH HHS/United States ; R01 GM061867/GM/NIGMS NIH HHS/United States ; R01 GM100021/GM/NIGMS NIH HHS/United States ; R01- GM61687/GM/NIGMS NIH HHS/United States ; R01-GM100021/GM/NIGMS NIH HHS/United States ; R01-GM93147/GM/NIGMS NIH HHS/United States
• Volume:
  42
• Issue:
  6
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:d6a04ab7fff12f89fc526ef9cc05d9d1b0680b95adaa86ab4205cc80a7bf5f88
• Download URL:
  https://stacks.cdc.gov/view/cdc/32200/cdc_32200_DS1.pdf
• File Type:
  [PDF - 5.59 MB ]