3UBN: Influenza hemagglutinin from the 2009 pandemic in complex with ligand 6SLN

Influenza virus hemagglutinin (HA) is the viral envelope protein that mediates viral attachment to host cells and elicits membrane fusion. The HA receptor-binding specificity is a key determinant for the host range and transmissibility of influenza viruses. In human pandemics of the 20th century, the HA normally has acquired specificity for human-like receptors before widespread infection. Crystal structures of the H1 HA from the 2009 human pandemic (A/California/04/2009 [CA04]) in complex with human and avian receptor analogs reveal conserved recognition of the terminal sialic acid of the glycan ligands. However, favorable interactions beyond the sialic acid are found only for alpha2-6-linked glycans and are mediated by Asp190 and Asp225, which hydrogen bond with Gal-2 and GlcNAc-3. For alpha2-3-linked glycan receptors, no specific interactions beyond the terminal sialic acid are observed. Our structural and glycan microarray analyses, in the context of other high-resolution HA structures with alpha2-6- and alpha2-3-linked glycans, now elucidate the structural basis of receptor-binding specificity for H1 HAs in human and avian viruses and provide a structural explanation for the preference for alpha2-6 siaylated glycan receptors for the 2009 pandemic swine flu virus.
PDB ID: 3UBNDownload
MMDB ID: 95290
PDB Deposition Date: 2011/10/24
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2.5079  Å
Source Organism:
Similar Structures:
Biological Unit for 3UBN: hexameric; determined by author and by software (PISA)
Molecular Components in 3UBN
Label Count Molecule
Proteins (6 molecules)
Hemagglutinin HA1
Molecule annotation
Hemagglutinin HA2
Molecule annotation
Chemicals (18 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB