Chain A ( A32 Y33 L35 S36 L37 Y38 L39 I40 Y41 K42 S43 P44 R45 Y46 N48 F50 G51 I52 Y54 F55 A119 I120 F204 K207 Q217 R218 L219 G220 Q221 E222 L223 L224 F225 F226 K227 E228 T229 V231 G267 L268 T269 F270 V271 F272 Y273 N274 R275 H276 T277 L278 K279 )