Chain A ( N7 F9 H12 F175 T261 F262 N263 G264 H265 N266 F267 D268 R270 C298 I299 Y300 E301 R302 N303 Q304 N315 T316 T317 F318 H319 V320 N321 N322 N323 I327 F328 F329 D330 L331 Y332 S333 F334 I335 Q336 K337 S338 E339 K340 L341 D342 S343 Y344 K345 L346 D347 S348 I349 S350 K351 N352 A353 L469 Y472 Y473 G474 V475 E476 T477 K478 T479 D480 A481 G482 A483 Y486 L488 P489 Q490 S491 M492 V493 F494 E495 Y496 R497 A498 S499 T500 I501 I502 S655 Y658 T659 Y660 I662 V663 A664 N665 S666 G827 )