Hemagglutinin Mini Model

The hemagglutinin protein (HA) of the influenza virus plays a critical role in the infection process. The virus binds to the cell and triggers receptor-mediated endocytosis. As a result of this endocytosis, the pH of the environment drops from pH 7 (outside the cell) to pH 5 (inside the endosome).  The hemagglutinin mini model shows the dramatically different structures of a region of the protein at these 2 different pHs.  The elongated version of the HA (at pH 5) is the active form, which leads to the fusion of the viral membrane with the cell membrane. Following membrane fusion, the viral RNAs are released into the cell, enabling the virus to replicate and spread throughout the body.

Our protein mini models magnet-dock onto the base and can be removed for closer examination. Color coding enables students to clearly see the conformational changes that the protein undergoes. Each alpha carbon backbone segment of the hemagglutinin is colored differently from the N-terminus to the C-terminus (red, blue, yellow, cyan, and white). The colors of the hemagglutinin at pH 7 (5HMG.pdb) correspond to the colors of the hemagglutinin at pH 5 (1HTM.pdb).

Molecule of the Month

The Molecule of the Month by scientist, author and artist Dr. David Goodsell includes an introduction to the structure and function of the chosen molecule and a discussion of its relevance to human health and welfare. Molecule of the Month articles are frequently referred to by teachers, students and researchers. More...