RK21 IVL70 RK74 PT79 IVL168 FYL264 DENGS268 P273 STA280 GS297 VIL309 G322 ILV328 P329 ED332 DE333 LMIVF336 LIFVM350 C357 G360 LIVFM361 DE362 IVL366 RK396 ILVF398 P399 PAS437 # found 27 key residues