id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-006935-wzz5t3sv	Gorbalenya, Alexander E.	Viral cysteine proteinases	1996		.txt	text/plain	8112	460	59	Only one conserved cysteine residue, thought to be the catalytic nucleophile, was identified in 3C p~° sequences of different origin [41, 47] and its indispensability for the PV 3C pr° proteolytic activity was proven by site-directed mutagenesis [48] . All RNA viral cysteine proteinases are synthesized as a domain in a polyprotein [17] and three major trends were discovered with respect to the position occupied by these enzymes. However, in an N-terminally extended precursor of 3C pr°, the Nterminal region of the proteinase could adopt a different structure that would fit the substrate binding pocket and might be processed in cis [5] . The $5-$2 subsites of the substrate-binding pocket, which interact with the less conserved P5-P2 positions of the cleavage sites, were recognized in the enzyme-substrate model of the HRV-14 3C pr° as well [5] .	./cache/cord-006935-wzz5t3sv.txt	./txt/cord-006935-wzz5t3sv.txt