Chain A ( I6 S7 N8 R9 D10 F11 V12 E13 D22 I23 V24 L25 E26 H27 G28 S29 C30 V31 T32 T33 M34 F43 E44 L45 K47 T48 Y137 T138 I139 M183 P187 R188 T189 G190 L191 F279 T280 G281 H282 L283 K284 C285 Q316 H317 F402 E403 T404 T405 M406 R407 G408 A409 K410 R411 M412 A413 I414 L415 G416 D417 T418 A419 W420 D421 F422 G423 S424 F429 T430 S431 G433 K434 H437 Q438 Y444 V451 W453 K456 V484 V485 T486 L487 Y488 L489 G490 A491 M492 V493 Q494 A495 )