Hemagglutinin trimer from the 1934 human H1 influenza virus. Hemagglutinin binds sialic acid on host cells and fuses the viral and cell membranes; it is the main target of flu vaccines.

Scientifically accurate model built directly from the experimental atomic coordinates of Protein Data Bank entry 1RU7 (X-ray crystallography, 2.30 angstrom resolution), biological assembly 1. Source organism: Influenza A virus (A/Puerto Rico/8/34(H1N1)). Only atoms that were resolved in the experiment are represented; nothing has been added or invented.

MODEL
- Molecular surface of every chain as a separate, named object (6 chains, 2 distinct components)
- 80,560 polygons, 80,560 vertices; all quads
- Every surface mesh is closed and manifold (no holes, no loose or overlapping vertices)
- One material per component (Principled BSDF); colours are easy to change. No textures needed
- Scale: 1 unit = 1 nanometer. Model centred at the origin, transforms clean, objects grouped under one parent

FORMATS
- Blender 4.0 (.blend), native, with the studio lighting and camera used for the previews (Cycles)
- FBX (.fbx)
- OBJ (.obj + .mtl)
- glTF 2.0 binary (.glb)
- USD (.usdc)
- STL (.stl), geometry only

Preview images were rendered in Blender Cycles. The wireframe image shows the actual mesh.

Structure reference: PDB 1RU7; Gamblin et al., Science, 2004 (doi:10.1126/science.1093155). PDB structure data are in the public domain (CC0 1.0).