6ymv

From Proteopedia

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

PDB ID 6ymv

Drag the structure with the mouse to rotate

Structural highlights

6ymv is a 4 chain structure with sequence from Saccharomyces cerevisiae and Saccharomyces cerevisiae S288C. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 3.1Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

MTF1_YEAST Mitochondrial transcription factor that confers selective promoter recognition on the core subunit of the yeast mitochondrial RNA polymerase. Interacts with DNA in a non-specific manner.

Publication Abstract from PubMed

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 UTPalphaS, 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.

Cryo-EM Structures Reveal Transcription Initiation Steps by Yeast Mitochondrial RNA Polymerase.,De Wijngaert B, Sultana S, Singh A, Dharia C, Vanbuel H, Shen J, Vasilchuk D, Martinez SE, Kandiah E, Patel SS, Das K Mol Cell. 2021 Jan 21;81(2):268-280.e5. doi: 10.1016/j.molcel.2020.11.016. Epub , 2020 Dec 4. PMID:33278362^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ De Wijngaert B, Sultana S, Singh A, Dharia C, Vanbuel H, Shen J, Vasilchuk D, Martinez SE, Kandiah E, Patel SS, Das K. Cryo-EM Structures Reveal Transcription Initiation Steps by Yeast Mitochondrial RNA Polymerase. Mol Cell. 2021 Jan 21;81(2):268-280.e5. PMID:33278362 doi:10.1016/j.molcel.2020.11.016