Immunogen sequence: TIRMIDAYTH LETFYNEEKD KKFAVIEDDS DEGGDDEYCD GDEDEDDLKK PLKLDETDRF LMTLFFENNK MLKRLAENPE YENEKLTKLR NTIMEQYTRT EESARGIIFT KTRQSAYALS QWITENEKFA EVGVKAHHLI GAGHSSEFKP. DEAD box proteins, characterized by the conserved motif Asp-Glu-Ala-