1IBN

NMR STRUCTURE OF HEMAGGLUTININ FUSION PEPTIDE IN DPC MICELLES AT PH 5

Summary for 1IBN

• Entry DOI: 10.2210/pdb1ibn/pdb
• Related: 1IBO
• Descriptor: HEMAGGLUTININ HA2 CHAIN PEPTIDE (1 entity in total)
• Functional Keywords: helix-kink-helix, viral protein
• Cellular location: Virion membrane; Single-pass type I membrane protein (Potential): P03442
• Total number of polymer chains: 1
• Total formula weight: 2054.28

Authors

Han, X.,Bushweller, J.H.,Cafiso, D.S.,Tamm, L.K. (deposition date: 2001-03-28, release date: 2001-08-08, Last modification date: 2024-05-22)

Primary citation

Han, X.,Bushweller, J.H.,Cafiso, D.S.,Tamm, L.K.
Membrane structure and fusion-triggering conformational change of the fusion domain from influenza hemagglutinin.
Nat.Struct.Biol., 8:715-720, 2001

PubMed Abstract: The N-terminal domain of the influenza hemagglutinin (HA) is the only portion of the molecule that inserts deeply into membranes of infected cells to mediate the viral and the host cell membrane fusion. This domain constitutes an autonomous folding unit in the membrane, causes hemolysis of red blood cells and catalyzes lipid exchange between juxtaposed membranes in a pH-dependent manner. Combining NMR structures determined at pHs 7.4 and 5 with EPR distance constraints, we have deduced the structures of the N-terminal domain of HA in the lipid bilayer. At both pHs, the domain is a kinked, predominantly helical amphipathic structure. At the fusogenic pH 5, however, the domain has a sharper bend, an additional 3(10)-helix and a twist, resulting in the repositioning of Glu 15 and Asp 19 relative to that at the nonfusogenic pH 7.4. Rotation of these charged residues out of the membrane plane creates a hydrophobic pocket that allows a deeper insertion of the fusion domain into the core of the lipid bilayer. Such an insertion mode could perturb lipid packing and facilitate lipid mixing between juxtaposed membranes.

PubMed: 11473264
DOI: 10.1038/90434

Experimental method

SOLUTION NMR