Chain A ( L613 S653 M752 S754 W760 I776 I777 K779 D782 D783 L784 R785 Q786 D787 M788 L789 L791 Y813 G814 C815 L816 P817 T818 G823 L824 I825 E826 V827 V828 L829 S831 D832 T833 A835 H895 D897 N898 M900 I910 D911 F912 G913 H914 L986 P987 E988 K1040 )