. 2022 Aug 19;27(16):5287. doi: 10.3390/molecules27165287

Table 1.

Structures with the different non-G tetrads mentioned in the text with their corresponding references and their PDB codes, when available.

Type		Tetrad	Cation	PDB
Homo		N1-H(N6) A	-	1EVM [13], 1NP9 [28]
		N3-H(N6) A	Na⁺	6A85 [14], 1MDG [26]
		N7-H(N6) A	-/Na⁺	1EVN [13], 1J6S [19]
		C₄	-/Ba²⁺/Na⁺	1EVO [9], 4U92 [10], 6A85 [14]
		T₄	-/Na⁺/K⁺	1EMQ [11], 6A85 [14], 4L0A [23], 1S47 [24]
		U₄	-	1RAU [15], 6GE1 [18], 1J6S [19], 1MDG [26], 1J8G [54], 2AWE [55], 4RKV [56], 4RJ1 [56], 4RNE [56], 4XK0 [57]
		I₄	K⁺	2GRB [21]
Base-paired	Major groove	Direct G:C:G:C	-/Na⁺	1XCE [29], 1A8N [30], 1A6H [31], 3R1E [34], 1JVC [35], 1NYD [58], 6SYK [59], 6SX6 [59]
		Slipped G:C:G:C	K⁺	1A8W [32], 7CV4 [33]
		Direct A:T:A:T	-/K⁺	1K8P [1]
		Slipped A:T:A:T	-/Na⁺	1XCE [29], 1JVC [35]
		Direct G:T:G:T	-	[36,37]
		Direct G:A:G:A	-	5M1L, 5M2L [39]
	Minor groove	Direct G:C:G:C	-	184D [41], 1MF5 [42], 1EU2 [43], 4ZKK [60], 5FHJ [61]
		Slipped G:C:G:C	-/divalent	6MC2, 6MC3, 6MC4, 6N4G [50], 2HK4 [45]
		Slipped C:G:G:C	-	2K8Z, 2K90, 2K97 [45]
		Direct G:T:G:T	-	-[48]
		Slipped G:T:G:T	-	1C11 [62], 2LSX [63], 7O5E [64]
		Slipped G:C:G:T	-	5OGA [65]
		Direct A:T:A:T	Na⁺	1EU6 [43], 284D [46]
		Direct G:C:A:T	Na⁺	1N96 [47]
		Slipped G:A:G:A	divalent	6MC2, 6MC3, 6MC4, 6N4G [50]