6a7f

Publication Abstract from PubMed

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 A. The major coat protein [protein 8 (p8)] consists of 47 residues that fold into a approximately 68-A-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 A and a twist of 38.52 degrees . 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, pi-pi 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.

Cryo-electron microscopy structure of the filamentous bacteriophage IKe.,Xu J, Dayan N, Goldbourt A, Xiang Y Proc Natl Acad Sci U S A. 2019 Feb 28. pii: 1811929116. doi:, 10.1073/pnas.1811929116. PMID:30819888^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.