Matrix of similar interfaces for 3D-footprint entry 1k3x_A

_ stats: contacts=5 Nring=3 specif=0.60
_ PDBs:  1:4pd2_A,
_ -lnE:  1:29.2,
_        1
0068 Q* RT
0069 L* MT
0070 Y  ET
0103 S  RC
0242 R* RT