PDBsum entry 4jpn

Viral protein

PDB id: 4jpn

Contents

Protein chains

(+ 4 more) 75 a.a.

Waters ×935

PDB id:

4jpn

Name:

Viral protein

Title:

Bacteriophage phix174 h protein residues 143-221

Structure:

Minor spike protein h. Chain: a, b, c, d, e, f, g, h, i, j. Fragment: coiled coil domain (unp residues 143-221). Synonym: h protein, pilot protein. Engineered: yes

Source:

Enterobacteria phage phix174. Organism_taxid: 10847. Gene: h. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

2.10Å R-factor: 0.176 R-free: 0.216

Authors:

L.Sun,L.N.Young,S.B.Boudko,A.Fokine,X.Zhang,M.G.Rossmann,B.A.Fane

Key ref:

L.Sun et al. (2014). Icosahedral bacteriophage ΦX174 forms a tail for DNA transport during infection. Nature, 505, 432-435. PubMed id: 24336205 DOI: 10.1038/nature12816

Date:

19-Mar-13 Release date: 11-Dec-13

Protein chains

P03646  (H_BPPHS) -  Minor spike protein H from Enterobacteria phage phiX174

Seq: 328 a.a.

Struc: 75 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1038/nature12816

Nature 505:432-435 (2014)

PubMed id: 24336205

Icosahedral bacteriophage ΦX174 forms a tail for DNA transport during infection.

L.Sun, L.N.Young, X.Zhang, S.P.Boudko, A.Fokine, E.Zbornik, A.P.Roznowski, I.J.Molineux, M.G.Rossmann, B.A.Fane.

ABSTRACT

Prokaryotic viruses have evolved various mechanisms to transport their genomes across bacterial cell walls. Many bacteriophages use a tail to perform this function, whereas tail-less phages rely on host organelles. However, the tail-less, icosahedral, single-stranded DNA ΦX174-like coliphages do not fall into these well-defined infection processes. For these phages, DNA delivery requires a DNA pilot protein. Here we show that the ΦX174 pilot protein H oligomerizes to form a tube whose function is most probably to deliver the DNA genome across the host's periplasmic space to the cytoplasm. The 2.4 Å resolution crystal structure of the in vitro assembled H protein's central domain consists of a 170 Å-long α-helical barrel. The tube is constructed of ten α-helices with their amino termini arrayed in a right-handed super-helical coiled-coil and their carboxy termini arrayed in a left-handed super-helical coiled-coil. Genetic and biochemical studies demonstrate that the tube is essential for infectivity but does not affect in vivo virus assembly. Cryo-electron tomograms show that tubes span the periplasmic space and are present while the genome is being delivered into the host cell's cytoplasm. Both ends of the H protein contain transmembrane domains, which anchor the assembled tubes into the inner and outer cell membranes. The central channel of the H-protein tube is lined with amide and guanidinium side chains. This may be a general property of viral DNA conduits and is likely to be critical for efficient genome translocation into the host.