6YMV

Cryo-EM structure of yeast mitochondrial RNA polymerase partially-melted transcription initiation complex (PmIC)

6YMV の概要

• エントリーDOI: 10.2210/pdb6ymv/pdb
• 関連するPDBエントリー: 6YMV 6YMW 8AP1 8ATV 8ATW 8C5S 8C5U 8Q63
• EMDBエントリー: 10845 10845 10846 15556 15662 15664 15665 16442 16443 18183
• 分子名称: Mitochondrial transcription factor 1, DNA-directed RNA polymerase, mitochondrial, DNA (33-MER) NON-TEMPLATE, ... (4 entities in total)
• 機能のキーワード: gene transcription, polymerase, rdrp, mtf1, rpo41, polrmt, mtrnap, dna, transcription initiation, rna polymerase, mitochondria, transcription
• 由来する生物種: Saccharomyces cerevisiae (strain ATCC 204508 / S288c); 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 204730.04

構造登録者

Das, K.,Patel, S.S. (登録日: 2020-04-10, 公開日: 2020-12-02, 最終更新日: 2023-10-18)

主引用文献

De Wijngaert, B.,Sultana, S.,Singh, A.,Dharia, C.,Vanbuel, H.,Shen, J.,Vasilchuk, D.,Martinez, S.E.,Kandiah, E.,Patel, S.S.,Das, K.
Cryo-EM Structures Reveal Transcription Initiation Steps by Yeast Mitochondrial RNA Polymerase.
Mol.Cell, 81:268-, 2021

PubMed Abstract: Mitochondrial RNA polymerase (mtRNAP) is crucial in cellular energy production, yet understanding of mitochondrial DNA transcription initiation lags that of bacterial and nuclear DNA transcription. We report structures of two transcription initiation intermediate states of yeast mtRNAP that explain promoter melting, template alignment, DNA scrunching, abortive synthesis, and transition into elongation. In the partially melted initiation complex (PmIC), transcription factor MTF1 makes base-specific interactions with flipped non-template (NT) nucleotides "AAGT" at -4 to -1 positions of the DNA promoter. In the initiation complex (IC), the template in the expanded 7-mer bubble positions the RNA and NTP analog UTPαS, while NT scrunches into an NT loop. The scrunched NT loop is stabilized by the centrally positioned MTF1 C-tail. The IC and PmIC states coexist in solution, revealing a dynamic equilibrium between two functional states. Frequent scrunching/unscruching transitions and the imminent steric clashes of the inflating NT loop and growing RNA:DNA with the C-tail explain abortive synthesis and transition into elongation.

PubMed: 33278362
DOI: 10.1016/j.molcel.2020.11.016

実験手法

ELECTRON MICROSCOPY (3.1 Å)