3TQ6

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

Summary for 3TQ6

• Entry DOI: 10.2210/pdb3tq6/pdb
• Descriptor: Transcription factor A, mitochondrial, DNA (5'-D(*TP*AP*AP*CP*AP*GP*TP*CP*AP*CP*CP*CP*CP*CP*CP*AP*AP*CP*(BRU)P*AP*AP*C)-3'), DNA (5'-D(*GP*TP*TP*AP*GP*TP*TP*GP*GP*GP*GP*GP*GP*TP*GP*AP*CP*TP*GP*TP*TP*A)-3'), ... (7 entities in total)
• Functional Keywords: transcription, transcription regulation, mitochondrion, dna-binding, hmgb-ubf_hmg-box, minor groove, tandem hmg boxes, transcription-dna complex, mitochondrial nucleoid, light-strand mitochondrial promoter, lsp, transcription/dna
• Biological source: Homo sapiens (human); More
• Cellular location: Mitochondrion: Q00059
• Total number of polymer chains: 6
• Total formula weight: 78993.82

Authors

Rubio-Cosials, A.,Sydow, J.F.,Jimenez-Menendez, N.,Fernandez-Millan, P.,Montoya, J.,Jacobs, H.T.,Coll, M.,Bernado, P.,Sola, M. (deposition date: 2011-09-09, release date: 2011-11-02, Last modification date: 2024-02-28)

Primary citation

Rubio-Cosials, A.,Sidow, J.F.,Jimenez-Menendez, N.,Fernandez-Millan, P.,Montoya, J.,Jacobs, H.T.,Coll, M.,Bernado, P.,Sola, M.
Human mitochondrial transcription factor A induces a U-turn structure in the light strand promoter.
Nat.Struct.Mol.Biol., 18:1281-1289, 2011

PubMed Abstract: 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°, 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.

PubMed: 22037172
DOI: 10.1038/nsmb.2160

Experimental method

X-RAY DIFFRACTION (2.45 Å)