id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-102336-ex3zlq38	De Wijngaert, Brent	Cryo-EM structures reveal transcription initiation steps by yeast mitochondrial RNA polymerase	2020-04-14		.txt	text/plain	2266	127	60	Cryo-EM structures of transcription pre-initiation complex (PIC) and initiation complex (IC) of yeast mitochondrial RNA polymerase show fully resolved transcription bubbles and explain promoter melting, template alignment, DNA scrunching, transition into elongation, and abortive synthesis. Hence, the structural basis for promoter melting, DNA scrunching, and transcription initiation remains largely unknown for the mtRNAPs. RPO41 (∆N100) and MTF1 were assembled on a pre-melted promoter (-21 to +12, 15S yeast mtDNA promoter; Fig. 1A ) to generate the yeast mitochondrial transcription preinitiation complex (y-mtPIC) (Fig. S1 ). The 3.7 Å density map of IC locates many previously uncharacterized structural elements, including the C-tail of MTF1 and the scrunched DNA ( Fig. 2B-C) , and reveals the mechanism of template alignment and RNA synthesis during initiation. During the transition, the upstream DNA from position -1 onward is locked in the MTF1 NT-groove while the template strand undergoes a large conformational switching to align with the 2-mer RNA and the incoming UTPaS at the active site ( Fig. 2C; Movie S2).	./cache/cord-102336-ex3zlq38.txt	./txt/cord-102336-ex3zlq38.txt