Chain A ( E42 V43 V44 D45 N46 A47 I48 D49 E50 L52 A53 G54 V71 Q72 D73 R76 G77 I78 P79 A90 A91 E92 V93 I94 M95 T96 V97 H99 A100 G101 G102 K103 F104 D105 G117 V118 G119 V120 S121 V122 V123 N124 I134 Q135 G164 T165 V167 )