Chain A ( T36 F42 Y46 C50 T51 A52 V53 L54 L55 C56 N57 S101 L102 L103 L104 N105 L106 L107 I108 S109 R112 T191 S192 T193 L194 I195 I196 T197 G198 I200 N201 F202 T204 E205 F223 F224 K225 Q226 S227 C228 I229 G230 G231 I232 T233 M234 I235 E263 M264 A265 H266 V267 L268 D269 G270 )