Chain A ( T418 A419 F420 I430 H811 L866 G867 L868 G869 D870 S871 F890 F891 Q892 V893 R894 G895 A896 V918 H919 T920 G921 V922 E924 G925 T926 S927 Q961 A962 Q963 A964 P965 G966 S967 A968 T969 T970 S971 L972 A973 )