4JPP

Bacteriophage phiX174 H protein residues 143-282

Summary for 4JPP

• Entry DOI: 10.2210/pdb4jpp/pdb
• Related: 4JPN
• Descriptor: Minor spike protein H (2 entities in total)
• Functional Keywords: helical barrel, tail tube, pilot dna during phage infection, viral protein
• Biological source: Enterobacteria phage phiX174
• Cellular location: Virion (Potential): P03646
• Total number of polymer chains: 5
• Total formula weight: 79768.24

Authors

Sun, L.,Young, L.N.,Boudko, S.B.,Fokine, A.,Zhang, X.,Rossmann, M.G.,Fane, B.A. (deposition date: 2013-03-19, release date: 2013-12-11, Last modification date: 2024-02-28)

Primary citation

Sun, L.,Young, L.N.,Zhang, X.,Boudko, S.P.,Fokine, A.,Zbornik, E.,Roznowski, A.P.,Molineux, I.J.,Rossmann, M.G.,Fane, B.A.
Icosahedral bacteriophage Phi X174 forms a tail for DNA transport during infection.
Nature, 505:431-435, 2014

PubMed 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.

PubMed: 24336205
DOI: 10.1038/nature12816

Experimental method

X-RAY DIFFRACTION (2.4 Å)