Chain A ( I2 I3 E4 P6 R7 I10 K11 V12 T13 G74 Y75 A76 I77 C175 P176 F471 Q472 N473 K474 A475 N476 V477 C478 W479 A480 K481 S482 L483 V484 P485 I486 W499 S500 Q501 I502 I503 Q504 A505 F506 K507 E508 D509 K510 A511 Y512 S513 P514 E515 V516 A517 L518 N519 E520 I521 C522 T523 R524 L530 L534 F535 V540 S541 V542 Y543 Y544 A545 D546 N547 H548 W549 D550 N551 R552 K556 F558 P597 L657 N667 L668 E669 L670 I686 H687 T688 P689 F690 R691 I692 Q696 Q697 C698 V699 D700 H701 A702 M703 K704 L705 Q706 M707 Y727 D731 T733 S734 R736 V737 )