Chain A ( I6 G7 G9 Q10 L11 S34 P35 L39 N56 L66 F67 L68 A69 V70 K71 P72 H73 I74 I75 P76 F77 I78 L79 D80 E81 I82 I86 V92 V93 S94 C95 A96 A97 G98 V99 S103 I104 K107 L108 N123 T124 T171 G175 S176 A260 S261 R264 T265 R266 L268 Q269 A272 D273 ),  Chain B ( N230 V231 S232 S233 P234 G235 G236 A237 T238 I239 H240 ),  Chain D ( V193 K194 M195 G196 )