Chain A ( R39 N42 A43 F44 L47 H103 V106 A107 N109 R110 L111 A113 V114 V115 Y116 P117 Y120 D193 V194 V195 T196 L197 A198 K199 I200 L201 A202 H203 R204 M207 R210 S211 S214 S215 S216 V217 R218 N219 E220 R221 E222 I223 L224 F225 F226 K227 Q228 S229 I277 F278 N279 I282 )