6A7F

The cryo-EM structure of filamentous bacteriophage IKe major coat protein p8 shell assembly.

Summary for 6A7F

• Entry DOI: 10.2210/pdb6a7f/pdb
• EMDB information: 6993 6994
• Descriptor: major coat protein p8 (1 entity in total)
• Functional Keywords: filamentous bacteriophage, major coat protein, viral protein
• Biological source: Filamentous phage
• Total number of polymer chains: 30
• Total formula weight: 171017.34

Authors

Xu, J.W.,Dayan, N.,Goldbourt, A.,Xiang, Y. (deposition date: 2018-07-03, release date: 2019-02-27, Last modification date: 2024-03-27)

Primary citation

Xu, J.,Dayan, N.,Goldbourt, A.,Xiang, Y.
Cryo-electron microscopy structure of the filamentous bacteriophage IKe.
Proc. Natl. Acad. Sci. U.S.A., 116:5493-5498, 2019

PubMed Abstract: The filamentous bacteriophage IKe infects cells bearing IncN pili. We report the cryo-electron microscopy structure of the micrometer-long IKe viral particle at a resolution of 3.4 Å. The major coat protein [protein 8 (p8)] consists of 47 residues that fold into a ∼68-Å-long helix. An atomic model of the coat protein was built. Five p8 helices in a horizontal layer form a pentamer, and symmetrically neighboring p8 layers form a right-handed helical cylinder having a rise per pentamer of 16.77 Å and a twist of 38.52°. The inner surface of the capsid cylinder is positively charged and has direct interactions with the encapsulated circular single-stranded DNA genome, which has an electron density consistent with an unusual left-handed helix structure. Similar to capsid structures of other filamentous viruses, strong capsid packing in the IKe particle is maintained by hydrophobic residues. Despite having a different length and large sequence differences from other filamentous phages, π-π interactions were found between Tyr9 of one p8 and Trp29 of a neighboring p8 in IKe that are similar to interactions observed in phage M13, suggesting that, despite sequence divergence, overall structural features are maintained.

PubMed: 30819888
DOI: 10.1073/pnas.1811929116

Experimental method

ELECTRON MICROSCOPY (3.4 Å)