Chain A ( G23 V24 T25 E68 P71 Y105 T107 S108 D109 L110 N114 Y115 D116 S117 K118 I119 K120 F158 W159 R160 L161 N162 D163 A164 L165 S166 L167 N191 V193 L194 G195 G196 H197 L198 K199 P200 )