id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-104037-39kk37fb	Ma, Jiahao	Cryo-EM structure of S-Trimer, a subunit vaccine candidate for COVID-19	2020-09-21		.txt	text/plain	2720	153	62	Cryo-EM structures of the WT and MT S-Trimers, determined at 3.2 Å and 2.6 Å respectively, revealed that both antigens adopt a tightly closed conformation and their structures are essentially identical to that of the previously solved full-length WT S protein in detergent. The newly-formed structural motif makes 152 direct contact with the previously identified pH switch 1 of the adjacent protomer, 153 accounting for the enhanced stability of the WT S-Trimer at lower pH (Fig. 3A) . When revisiting the electron density map for full-163 length wild-type S protein (EMDB: 22292), we spotted unassigned density at the become predominant over the ancestral form worldwide and has been shown to interaction with K854 at the conformational switch region (Fig. 4C ). Purified MT S-trimer protein diluted to 0.2 and 0.5 mg/ml in PBS buffer were applied to glow-discharged gold holey carbon 1.2/1.3 300-mesh grids with and without graphene oxide, respectively.	./cache/cord-104037-39kk37fb.txt	./txt/cord-104037-39kk37fb.txt