Matrix of similar interfaces for 3D-footprint entry 1a6y_A

_ stats: contacts=4 Nring=4 specif=1.00
_ PDBs:  1:2a66_A,
_ -lnE:  1:11.0,
_        1
0020 E* EC
0023 K* KG
0027 R* KG
0028 R* RG