Ligand Atom Receptor Atom Distance -- C 39 HIS O A 99 SER O 2.66 C 39 HIS O A 62 ASN ND2 2.78 C 42 HIS NE2 A 218 ASN O 2.88 C 101 GLU OE1 A 61 GLY O 2.93 C 39 HIS C A 99 SER O 3.00