PDBsum entry 1qu1

Viral protein

PDB id: 1qu1

Contents

Protein chains

133 a.a.

144 a.a.

155 a.a.

Waters ×734

PDB id:

1qu1

Name:

Viral protein

Title:

Crystal structure of eha2 (23-185)

Structure:

Protein (influenza recombinant ha2 chain). Chain: a, b, c, d, e, f. Engineered: yes

Source:

Influenza a virus. Organism_taxid: 11320. Expressed in: escherichia coli. Expression_system_taxid: 562

Biol. unit:

Trimer (from PQS)

Resolution:

1.90Å R-factor: 0.229 R-free: 0.250

Authors:

J.Chen,J.J.Skehel,D.C.Wiley

Key ref:

J.Chen et al. (1999). N- and C-terminal residues combine in the fusion-pH influenza hemagglutinin HA(2) subunit to form an N cap that terminates the triple-stranded coiled coil. Proc Natl Acad Sci U S A, 96, 8967-8972. PubMed id: 10430879 DOI: 10.1073/pnas.96.16.8967

Date:

05-Jul-99 Release date: 05-Jan-00

Protein chain

P03437  (HEMA_I68A0) -  Hemagglutinin from Influenza A virus (strain A/Aichi/2/1968 H3N2)

Seq: 566 a.a.

Struc: 133 a.a.*

Protein chains

P03437  (HEMA_I68A0) -  Hemagglutinin from Influenza A virus (strain A/Aichi/2/1968 H3N2)

Seq: 566 a.a.

Struc: 144 a.a.*

Protein chain

P03437  (HEMA_I68A0) -  Hemagglutinin from Influenza A virus (strain A/Aichi/2/1968 H3N2)

Seq: 566 a.a.

Struc: 155 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

DOI no: 10.1073/pnas.96.16.8967

Proc Natl Acad Sci U S A 96:8967-8972 (1999)

PubMed id: 10430879

N- and C-terminal residues combine in the fusion-pH influenza hemagglutinin HA(2) subunit to form an N cap that terminates the triple-stranded coiled coil.

J.Chen, J.J.Skehel, D.C.Wiley.

ABSTRACT

The structure of a stable recombinant ectodomain of influenza hemagglutinin HA(2) subunit, EHA(2) (23-185), defined by proteolysis studies of the intact bacterial-expressed ectodomain, was determined to 1.9-A resolution by using x-ray crystallography. The structure reveals a domain composed of N- and C-terminal residues that form an N cap terminating both the N-terminal alpha-helix and the central coiled coil. The N cap is formed by a conserved sequence, and part of it is found in the neutral pH conformation of HA. The C-terminal 23 residues of the ectodomain form a 72-A long nonhelical structure ordered to within 7 residues of the transmembrane anchor. The structure implies that continuous alpha helices are not required for membrane fusion at either the N or C termini. The difference in stability between recombinant molecules with and without the N cap sequences suggests that additional free energy for membrane fusion may become available after the formation of the central triple-stranded coiled coil and insertion of the fusion peptide into the target membrane.

Selected figure(s)

Figure 4.
Fig. 4. N cap domain of EHA[2](23-185). (A) Stereo ribbon diagram of the N-terminal residues (dark blue, dark red, dark yellow) and the C-terminal residues (light colors) of EHA[2] (23-185), viewed down the molecular threefold-symmetry axis. (B) Stereoatomic diagram of the N-terminal residues (colors and view as in A) and the C-terminal residues of EHA[2] (23-185). Potential hydrogen bonds are green dashed lines. (C) Stereoribbon diagram as in A but viewed perpendicular to the molecular threefold-symmetry axis. (D) Stereoatomic diagram as in B but viewed as in C. Figure prepared with RIBBONS (43).

Figure 5.
Fig. 5. Comparison of TBHA[2] from low pH-treated HA and EBHA[2](23-185). (A) TBHA[2] (residues 1-27 of HA[1] and 38-175 of HA[2]) from thermolytic digestion of low pH-treated viral BHA. The white molecular surface is the central triple-stranded coiled coil. The atomic models are the C-terminal residues beyond residue 106 colored differently for each monomer. The last residues visible in the electron density at the termini are labeled. (B) EBHA[2] (23-185) with the N-terminal residues from 34 to 40 colored yellow. The rendering is as in A with the visible terminal residues labeled. Figure prepared with GRASP (44).

Figures were selected by an automated process.