3tq6 | pdb_00003tq6

Crystal structure of human mitochondrial transcription factor A, TFAM or mtTFA, bound to the light strand promoter LSP

spinqualitylabelsall models 3tq6, resolution 2.45Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3tq6 is a 6 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: 1PE, PEG, PO4 NonStd Res: BRU Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [TFAM_HUMAN] Binds to the mitochondrial light strand promoter and functions in mitochondrial transcription regulation. Required for accurate and efficient promoter recognition by the mitochondrial RNA polymerase. Promotes transcription initiation from the HSP1 and the light strand promoter by binding immediately upstream of transcriptional start sites. Is able to unwind DNA. Bends the mitochondrial light strand promoter DNA into a U-turn shape via its HMG boxes. Required for maintenance of normal levels of mitochondrial DNA. May play a role in organizing and compacting mitochondrial DNA. Publication Abstract from PubMed Human mitochondrial transcription factor A, TFAM, is essential for mitochondrial DNA packaging and maintenance and also has a crucial role in transcription. Crystallographic analysis of TFAM in complex with an oligonucleotide containing the mitochondrial light strand promoter (LSP) revealed two high-mobility group (HMG) protein domains that, through different DNA recognition properties, intercalate residues at two inverted DNA motifs. This induced an overall DNA bend of ~180 degrees , stabilized by the interdomain linker. This U-turn allows the TFAM C-terminal tail, which recruits the transcription machinery, to approach the initiation site, despite contacting a distant DNA sequence. We also ascertained that structured protein regions contacting DNA in the crystal were highly flexible in solution in the absence of DNA. Our data suggest that TFAM bends LSP to create an optimal DNA arrangement for transcriptional initiation while facilitating DNA compaction elsewhere in the genome. Human mitochondrial transcription factor A induces a U-turn structure in the light strand promoter.,Rubio-Cosials A, Sidow JF, Jimenez-Menendez N, Fernandez-Millan P, Montoya J, Jacobs HT, Coll M, Bernado P, Sola M Nat Struct Mol Biol. 2011 Oct 30;18(11):1281-9. doi: 10.1038/nsmb.2160. PMID:22037172 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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