Hydration sites of unpaired RNA bases: a statistical analysis of the PDB structures

BMC Structural Biology

Table 4 Other non-bonding interactions around unpaired RNA bases

	Interactions with RNA atoms			Crystal packing interactions			Interactions with atoms of proteins, ligands, and ions
Base	N _b *	N _a **	d	N _b *	N _a **	d	N _b *	N _a **	d
Adenine	7	92	5	25	325	12	87	1.868	55
Guanine	7	93	5	20	258	11	96	2.381	68
Cytosine	7	41	-	10	98	5	33	532	19
Uracil	5	30	-	30	351	13	75	1.071	34

Number of the unpaired RNA bases participating in the atom-atom interactions within 5 Å and number of atoms around these unpaired bases. For example, 25 from 197 unpaired adenine bases (see the numbers of the unpaired bases in Table 1) have crystal packing contacts within 5 Å and the number of surrounding atoms that participate in these interactions is 325. The empirical parameter d, used for cluster detection (see Method section), is also reported for each type of interaction.
* - number of unpaired bases.
** - number of atoms surrounding the base

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