Chain A ( S560 T562 I564 D565 P566 T567 W575 L588 K595 V596 V597 E598 A614 V615 K616 S632 E633 I636 M637 S638 H639 L640 G641 Q642 H643 E644 N645 I646 V647 N648 L649 L650 V661 I662 T663 E664 Y665 C666 G669 D670 F768 L769 A770 S771 K772 N773 C774 I775 H776 R777 D778 R782 N783 L785 T787 K793 I794 G795 D796 F797 G798 L799 A800 R801 I803 Y809 V834 D837 )