PDBsum entry 4s1x

Viral protein

PDB id: 4s1x

Contents

Protein chains

38 a.a.

37 a.a.

22 a.a.

Ligands

GOL

Waters ×54

PDB id:

4s1x

Name:

Viral protein

Title:

Crystal structure of ha2-del-l2sem, central coiled-coil from influenza hemagglutinin ha2 without heptad repeat stutter

Structure:

Truncated hemagglutinin. Chain: a, b, c, d, e, f. Engineered: yes

Source:

Synthetic: yes. Unidentified influenza virus. Organism_taxid: 11309. Other_details: peptide synthesis

Resolution:

1.90Å R-factor: 0.210 R-free: 0.246

Authors:

V.N.Malashkevich,C.D.Higgins,J.R.Lai,S.C.Almo

Key ref:

V.N.Malashkevich et al. (2015). A switch from parallel to antiparallel strand orientation in a coiled-coil X-ray structure via two core hydrophobic mutations. Biopolymers, 104, 178-185. PubMed id: 25753192 DOI: 10.1002/bip.22631

Date:

15-Jan-15 Release date: 01-Apr-15

Protein chains

A8TXX2  (A8TXX2_9ORTO) -  Truncated hemagglutinin (Fragment) from unidentified influenza virus

Seq: 81 a.a.

Struc: 38 a.a.*

Protein chains

A8TXX2  (A8TXX2_9ORTO) -  Truncated hemagglutinin (Fragment) from unidentified influenza virus

Seq: 81 a.a.

Struc: 37 a.a.*

Protein chains

A8TXX2  (A8TXX2_9ORTO) -  Truncated hemagglutinin (Fragment) from unidentified influenza virus

Seq: 81 a.a.

Struc: 22 a.a.*

* PDB and UniProt seqs differ at 10 residue positions (black crosses)

DOI no: 10.1002/bip.22631

Biopolymers 104:178-185 (2015)

PubMed id: 25753192

A switch from parallel to antiparallel strand orientation in a coiled-coil X-ray structure via two core hydrophobic mutations.

V.N.Malashkevich, C.D.Higgins, S.C.Almo, J.R.Lai.

ABSTRACT

The coiled-coil is one of the most ubiquitous and well studied protein structural motifs. Significant effort has been devoted to dissecting subtle variations of the typical heptad repeat sequence pattern that can designate larger topological features such as relative α-helical orientation and oligomer size. Here we report the X-ray structure of a model coiled-coil peptide, HA2-Del-L2seM, which forms an unanticipated core antiparallel dimer with potential sites for discrete higher-order multimerization (trimer or tetramer). In the X-ray structure, a third, partially-ordered α-helix is weakly associated with the antiparallel dimer and analytical ultracentrifugation experiments indicate the peptide forms a well-defined tetramer in solution. The HA2-Del-L2seM sequence is closely related to a parent model peptide, HA2-Del, which we previously reported adopts a parallel trimer; HA2-Del-L2seM differs by only hydrophobic leucine to selenomethione mutations and thus this subtle difference is sufficient to switch both relative α-helical topology and number of α-helices participating in the coiled-coil. Comparison of the X-ray structures of HA2-Del-L2seM (reported here) with the HA2-Del parent (reported previously) reveals novel interactions involving the selenomethionine residues that promote antiparallel coiled-coil configuration and preclude parallel trimer formation. These novel atomic insights are instructive for understanding subtle features that can affect coiled-coil topology and provide additional information for design of antiparallel coiled-coils. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 178-185, 2015.