Chain A ( T130 V131 S132 N133 L134 T135 L136 A138 I195 K196 H197 L198 R199 V200 F201 F202 V203 T204 A205 A206 W207 C242 F245 A246 V248 A249 D250 R251 L253 L254 E276 D826 A827 I829 G830 N831 T833 G834 )