Chain A ( D280 L281 S284 H285 E672 V675 P678 M679 L680 K682 P683 Q684 K685 S983 N984 D985 N1151 H1154 S1155 V1156 K1157 F1158 S1167 S1168 E1169 S1171 T1172 V1173 )