Four hydrogen bonds formed between B45Lys and A109Gln and B45Lys and A105Gln of the NMR ensemble of the SMN-Gemin2 complex (PDB ID: 2leh) [21].

Apart from those mentioned in this table, no more hydrogen bond or salt bridge was found for B45Lys. In the first row, HB represents hydrogen bond, D − A and H − A represent the distance between donor and acceptor and hydrogen and acceptor, respectively. HB1, HB2, HB3 and HB4 represent hydrogen bonds that were computationally identified from the eighth, the eighth, the nineteenth and the eleventh structure models of the SMN-Gemin2 complex (PDB ID: 2leh, NumMDL = 32). The unshaded rows represent the values of D − A, H − A and ∠ADH for the hydrogen bonds. The shaded rows represent the the distributions of D − A, H − A and ∠ADH for the 32 NMR structure models in the SMN-Gemin2 complex, i.e., the mean ± one standard deviation of the distances or the ∠ADH angles for the hydrogen bonds. The residue naming scheme is the same as that used in Table 3.