Chain A ( L544 G545 E546 G547 A548 F549 G550 V552 A570 K572 L574 F585 E588 A589 L591 L592 V601 F603 M615 V616 F617 E618 Y619 M620 K621 G623 D624 L625 N626 K627 L670 F675 H677 D679 A681 T682 R683 N684 C685 L686 V687 G688 V693 K694 I695 G696 D697 F698 G699 M700 S701 R702 V704 D708 Y709 M731 )