Chain A ( H703 D709 T710 S711 S712 S713 L714 L715 T716 S717 L718 N719 Q720 W755 M756 L763 L776 F778 L782 I783 L784 R788 M789 K790 E791 S792 S793 F794 Y795 S796 L797 C798 L799 M801 W802 Y890 C891 N893 T894 Q897 L901 S902 V903 E904 F905 M909 )