Chain A ( L579 D580 N581 N582 V591 D592 K593 R594 V595 Q596 S597 C598 V642 Y643 D644 I645 A646 D647 I989 K990 Y997 G1000 L1001 Y1002 L1003 F1004 F1019 C1020 Y1021 L1022 S1023 Q1024 C1025 S1026 G1027 R1028 L1029 N1030 P1031 N1032 L1033 Y1034 D1035 K1038 V1039 K1040 S1067 I1068 Q1069 L1071 I1072 L1073 P1077 Y1078 E1081 N1096 C1099 Y1100 M1103 A1104 L1105 I1106 R1107 V1108 V1109 Q1110 S1111 M1112 T1113 Q1114 L1115 V1116 R1117 R1118 P1119 P1120 I1127 F1131 K1267 S1268 G1271 V1272 L1273 T1274 Q1275 F1276 R1277 A1279 L1280 M1285 )