6YMV
Cryo-EM structure of yeast mitochondrial RNA polymerase partially-melted transcription initiation complex (PmIC)
Summary for 6YMV
| Entry DOI | 10.2210/pdb6ymv/pdb |
| Related | 6YMV 6YMW 8AP1 8ATV 8ATW 8C5S 8C5U 8Q63 |
| EMDB information | 10845 10845 10846 15556 15662 15664 15665 16442 16443 18183 |
| Descriptor | Mitochondrial transcription factor 1, DNA-directed RNA polymerase, mitochondrial, DNA (33-MER) NON-TEMPLATE, ... (4 entities in total) |
| Functional Keywords | gene transcription, polymerase, rdrp, mtf1, rpo41, polrmt, mtrnap, dna, transcription initiation, rna polymerase, mitochondria, transcription |
| Biological source | Saccharomyces cerevisiae (strain ATCC 204508 / S288c) More |
| Total number of polymer chains | 4 |
| Total formula weight | 204730.04 |
| Authors | Das, K.,Patel, S.S. (deposition date: 2020-04-10, release date: 2020-12-02, Last modification date: 2023-10-18) |
| Primary citation | 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 Cited by 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: 33278362DOI: 10.1016/j.molcel.2020.11.016 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.1 Å) |
Structure validation
Download full validation report
