Chain A ( Q65 R66 E67 A68 E69 L70 K71 K72 K73 K74 L75 E76 Q77 R78 S79 K80 L81 E82 N83 L84 E85 D86 L87 E88 I89 I90 I91 Q92 L93 K94 K95 R96 K97 K98 Y99 R100 K101 K103 )