id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-349672-2kt7xw8i	Dasgupta, Tumpa	Mechanism of Type IA Topoisomerases	2020-10-17		.txt	text/plain	8538	463	53	Here, based on available structural and biochemical data, we discuss how a type IA topoisomerase may recognize and bind single-stranded DNA or RNA to initiate its required catalytic function. In type IA topoisomerases, the hydroxyl group in the side chain of the active site tyrosine residue is responsible for the first nucleophilic attack on the scissile phosphate of a single-stranded DNA resulting in the cleavage of the G-strand and the formation of the transient 5 -phospho-tyrosyl covalent linkage [66] . Though the type IA topoisomerase core domain that forms the characteristic torus structure contains all the highly conserved motifs responsible for G-strand binding and cleavage religation, the C-terminal domains of bacterial topoisomerase I have been shown to be required for removing negative supercoils from DNA rapidly in a processive mechanism [61, 72, [84] [85] [86] [87] .	./cache/cord-349672-2kt7xw8i.txt	./txt/cord-349672-2kt7xw8i.txt