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Publication Abstract from PubMed

The acid-stable capsid structures of Helicobacter pylori phages KHP30 and KHP40 are solved at 2.7 and 3.0 A resolutions by cryoelectron microscopy, respectively. The capsids have icosahedral T = 9 symmetry and consist of each 540 copies of 2 structural proteins, a major capsid protein, and a cement protein. The major capsid proteins form 12 pentagonal capsomeres occupying icosahedral vertexes and 80 hexagonal capsomeres located at icosahedral faces and edges. The major capsid protein has a unique protruding loop extending to the neighboring subunit that stabilizes hexagonal capsomeres. Furthermore, the capsid is decorated with trimeric cement proteins with a jelly roll motif. The cement protein trimer sits on the quasi-three-fold axis formed by three major capsid protein capsomeres, thereby enhancing the particle stability by connecting these capsomeres. Sequence and structure comparisons between the related Helicobacter pylori phages suggest a possible mechanism of phage adaptation to the human gastric environment.

Acid-stable capsid structure of Helicobacter pylori bacteriophage KHP30 by single-particle cryoelectron microscopy.,Kamiya R, Uchiyama J, Matsuzaki S, Murata K, Iwasaki K, Miyazaki N Structure. 2021 Sep 27. pii: S0969-2126(21)00329-4. doi:, 10.1016/j.str.2021.09.001. PMID:34597601^[1]

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