Influenza hemagglutinin protein terminus

Chapman and Liljas, Fig. 8. The structure of influenza hemagglutinin (Wilson et al., 1981). The strands of the jelly-roll domain (top) are denoted 1 through 8. The color scheme is blue to red from the N terminus of chain 1 (Nt 1) to the C terminus of chain 2 (Ct 2), which is cleaved from the membrane anchor. The fusion peptide is at the N terminus of chain 2 (Nt 2). In the virus, the protein forms a trimer where the long helices are parallel to the 3-fold axis and form a stem. 

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