id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-355676-2y8vowbi	Liu, Pinghua	A Previously Unrecognized Unr Stem-Loop Structure in the Coronavirus 5’ Untranslated Region Plays a Functional role in Replication	2006		.txt	text/plain	1329	76	62	The RNA secondary structure prediction algorithm Vienna RNA 1.5 4 was used to predict the secondary structures of group 1 and group 2 coronavirus 5' UTRs. A reverse genetic system based on in vitro assembly of cloned cDNAs (A-G) was used to recover wild-type MHV-A59 1000 and mutant viruses. The assembled fragment containing either the wild-type sequence, or with mutations in SL2, was ligated into MHV-A59-1000 RNA was electroporated into BHK-R cells to recover infectious virus as described. Analysis of the entire 30 kb MHV and SARS-CoV genomes reveals that SL2-like stem loops are extremely rare (appearing just 3 and 5 other times, respectively); this suggests an important role in coronavirus replication. Consistent with the predicted structure of the UNR loop, the U49A mutant was viable and produced a virus with a near normal plaque size (Figs 4A-B) .	./cache/cord-355676-2y8vowbi.txt	./txt/cord-355676-2y8vowbi.txt