Download MendeleyCryo-electron microscopy structure of the filamentous bacteriophage IKe.
Xu, J., Dayan, N., Goldbourt, A., Xiang, Y.(2019) Proc Natl Acad Sci U S A 116: 5493-5498
- PubMed: 30819888
- DOI: https://doi.org/10.1073/pnas.1811929116
- Primary Citation of Related Structures:
6A7F - PubMed Abstract:
The filamentous bacteriophage IKe infects Escherichia coli 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.
Organizational Affiliation:
Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing 100084, China.
