9MN7

Structure of the human mitochondrial late-stage transcription initiation complex, IC8

9MN7 の概要

• エントリーDOI: 10.2210/pdb9mn7/pdb
• EMDBエントリー: 48415
• 分子名称: Dimethyladenosine transferase 2, mitochondrial, DNA-directed RNA polymerase, mitochondrial, Non-Template Strand DNA, ... (7 entities in total)
• 機能のキーワード: mitochondrial rna polymerase, transcription initiation complex, transcription, polrmt, transcription-dna-rna complex
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 227415.87

構造登録者

Herbine, K.H.,Nayak, A.R.,Temiakov, D. (登録日: 2024-12-20, 公開日: 2025-08-06, 最終更新日: 2025-09-03)

主引用文献

Herbine, K.,Nayak, A.R.,Zamudio-Ochoa, A.,Temiakov, D.
Structural basis for promoter recognition and transcription factor binding and release in human mitochondria.
Mol.Cell, 85:3123-3136.e7, 2025

PubMed Abstract: Transcription in human mitochondria is driven by a core apparatus consisting of a Pol A family RNA polymerase (mtRNAP), the initiation factors TFAM and TFB2M, and the elongation factor TEFM. While earlier structures of initiation and elongation complexes provided valuable snapshots, they represent isolated stages of a highly dynamic and multistep process. Critical aspects of mitochondrial transcription-such as DNA recognition and melting, promoter escape, and the release of initiation factors-remain poorly understood. Here, we present a series of cryoelectron microscopy (cryo-EM) structures that capture the transcription complex as it transitions from the initial open promoter complex to the processive elongation complex through intermediate stages. Our data reveal new, previously unidentified determinants of promoter specificity: the sequential disengagement of mtRNAP from TFAM and the promoter, the release of TFB2M, and the recruitment of TEFM. Together, these findings provide a detailed molecular mechanism underlying transcription in human mitochondria.

PubMed: 40712587
DOI: 10.1016/j.molcel.2025.06.016

実験手法

ELECTRON MICROSCOPY (2.65 Å)