Table 3.

List of all possible hydrogen bonding interactions as observed in the crystal structures for compounds 1–4. The hydrogen bond distance cutoff for the analysis is 3.6 Å or less.

NNRTI	Donor	Acceptor	Distance	Total Possible H bonds	Uracil Conformation
4
	NH backbone K103	CO uracil	3.3	2	Intermediate
	NH uracil	CO P236 backbone	3.4
3
	NH backbone K103	CO uracil	3.2	2	aag
	NH uracil	CO P236 backbone	3.6
2
	NH backbone K103	CO uracil	2.9	4	sag
	NH uracil	CO K103 backbone	2.8
	NH uracil	CO P236 backbone	3.2
	NH3 sidechain K102	CO uracil	3.2
1
	NH backbone K103	CO uraci	3.2	4	sag
	NH uracil	CO K103 backbone	3.3
	NH uracil	CO P236 backbone	3.4
	NH3 sidechain K102	CO uracil	3.5