Crystallization and preliminary X-ray diffraction studies of the influenza C virus glycoprotein

Influenza C virus contains a single surface glycoprotein in its lipid envelope which is the hemagglutinin-esterase-fusion glycoprotein (HEF). HEF binds cell-surface receptors, is a receptor-destroying enzyme (a 9-O-acetylesterase), and mediates the fusion of virus and host cell membranes. A bromelain-released soluble form of HEF has been crystallized. Two different tetragonal forms have been identified from crystals with the same morphology [P₁₍₃₎22, a = b = 154.5, c = 414.4 Å, and P4₁₍₃₎2₁2, a = b = 217.4, c = 421.4 Å]. Both crystal forms share a common packing scheme. Synchrotron data collection and flash cooling of crystals have been used for high-resolution data collection.