Phage capsid protein-directed MnO2 nanosheets with peroxidase-like activity for spectrometric biosensing and evaluation of antioxidant behaviour

The phAPEC6 genome encodes 551 predicted gene products, with the vast majority (83%) of unknown function. Of these, 62 have been identified as virion-associated proteins by mass spectrometry (ESI-MS/MS), including the major capsid protein (Gp225; present in 1620 copies), which shows a HK97 capsid protein-based fold. Cryo-electron microscopy experiments showed that the 350-kbp DNA molecule of Escherichia coli virus phAPEC6 is packaged in at least 15 concentric layers in the phage capsid. A capsid inner body rod is also present, measuring about 91 nm by 18 nm and oriented along the portal axis. In the phAPEC6 contractile tail, 25 hexameric stacked rings can be distinguished, built of the identified tail sheath protein (Gp277). Cryo-EM reconstruction reveals the base of the unique hairy fibers observed during an initial transmission electron microscopy (TEM) analysis. These very unusual filaments are ordered at three annular positions along the contractile sheath, as well as around the capsid, and may be involved in host interaction.

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Anchoring of a hydrophobic heptapeptide (AFILPTG) on silica facilitates peptide unfolding at the abiotic-biotic interface

Physical Chemistry Chemical Physics ◽

10.1039/d1cp02072b ◽

2021 ◽

Author(s):

Victor V Volkov ◽

Hendrik Heinz ◽

Carole Celia Perry

Keyword(s):

Capsid Protein ◽

Negative Charge ◽

Silica Particles ◽

Binding Activity ◽

Phage Capsid

A hydrophobic heptapeptide, sequence AFILPTG, as part of a phage capsid protein binds effectively to silica particles carrying negative charge. Here, we explore the silica binding activity of the sequence...

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The TolQRA Proteins Are Required for Membrane Insertion of the Major Capsid Protein of the Filamentous Phage f1 during Infection

Journal of Bacteriology ◽

10.1128/jb.180.7.1723-1728.1998 ◽

1998 ◽

Vol 180 (7) ◽

pp. 1723-1728 ◽

Cited By ~ 47

Author(s):

Eva Marie Click ◽

Robert E. Webster

Keyword(s):

Capsid Protein ◽

Phage Particle ◽

Cytoplasmic Membrane ◽

Major Capsid Protein ◽

Infection Process ◽

Dna Transfer ◽

Filamentous Phage ◽

Membrane Insertion ◽

Phage Dna ◽

Phage Capsid

ABSTRACT Infection of Escherichia coli by the filamentous bacteriophage f1 is initiated by interaction of the end of the phage particle containing the gene III protein with the tip of the F conjugative pilus. This is followed by the translocation of the phage DNA into the cytoplasm and the insertion of the major phage capsid protein, pVIII, into the cytoplasmic membrane. DNA transfer requires the chromosomally encoded TolA, TolQ, and TolR cytoplasmic membrane proteins. By using radiolabeled phages, it can be shown that no pVIII is inserted into the cytoplasmic membrane when the bacteria contain null mutations in tolQ, -R and -A. The rate of infection can be varied by using bacteria expressing various mutant TolA proteins. Analysis of the infection process in these strains demonstrates a direct correlation between the rate of infection and the incorporation of infecting bacteriophage pVIII into the cytoplasmic membrane.

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Efficient affinity-tagging of M13 phage capsid protein IX for immobilization of protein III-displayed oligopeptide probes on abiotic platforms

Applied Microbiology and Biotechnology ◽

10.1007/s00253-019-10338-8 ◽

2020 ◽

Vol 104 (3) ◽

pp. 1201-1209

Author(s):

Zhou Tong ◽

Laura A. Silo-Suh ◽

Anwar Kalalah ◽

Paul Dawson ◽

Bryan A. Chin ◽

...

Keyword(s):

Capsid Protein ◽

Phage Capsid ◽

M13 Phage ◽

Protein Ix

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Shape shifter: redirection of prolate phage capsid assembly by staphylococcal pathogenicity islands

Nature Communications ◽

10.1038/s41467-021-26759-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

N’Toia C. Hawkins ◽

James L. Kizziah ◽

José R. Penadés ◽

Terje Dokland

Keyword(s):

Electron Microscopy ◽

Staphylococcus Aureus ◽

Capsid Protein ◽

Pathogenicity Islands ◽

Size And Shape ◽

Cryo Electron Microscopy ◽

Phage Multiplication ◽

End Caps ◽

Phage Capsid ◽

Preferential Incorporation

AbstractStaphylococcus aureus pathogenicity islands (SaPIs) are molecular parasites that hijack helper phages for their transfer. SaPIbov5, the prototypical member of a family of cos type SaPIs, redirects the assembly of ϕ12 helper capsids from prolate to isometric. This size and shape shift is dependent on the SaPIbov5-encoded protein Ccm, a homolog of the ϕ12 capsid protein (CP). Using cryo-electron microscopy, we have determined structures of prolate ϕ12 procapsids and isometric SaPIbov5 procapsids. ϕ12 procapsids have icosahedral end caps with Tend = 4 architecture and a Tmid = 14 cylindrical midsection, whereas SaPIbov5 procapsids have T = 4 icosahedral architecture. We built atomic models for CP and Ccm, and show that Ccm occupies the pentameric capsomers in the isometric SaPIbov5 procapsids, suggesting that preferential incorporation of Ccm pentamers prevents the cylindrical midsection from forming. Our results highlight that pirate elements have evolved diverse mechanisms to suppress phage multiplication, including the acquisition of phage capsid protein homologs.

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The presence of Chlamydia phage PhiCPG1 capsid protein VP1 genes and antibodies in patients infected with Chlamydia trachomatis

Acta Biochimica Polonica ◽

10.18388/abp.2015_1185 ◽

2016 ◽

Vol 63 (3) ◽

Cited By ~ 2

Author(s):

Jingyue Ma ◽

Yuan Liu ◽

Yuanjun Liu ◽

Lingjie Li ◽

Shuping Hou ◽

...

Keyword(s):

Chlamydia Trachomatis ◽

Western Blot ◽

Capsid Protein ◽

Pcr Amplification ◽

Antibody Test ◽

Vp1 Gene ◽

Western Blot Assay ◽

Phage Capsid ◽

Capsid Protein Vp1 ◽

Guinea Pig Model

Chlamydia phage PhiCPG1 has been found in Chlamydia caviae in a guinea pig model for inclusion conjunctivitis, raising the possibility that Chlamydia phage is also present in patients infected with C. trachomatis (Ct). In the present study, we assayed for presence of Chlamydia phage capsid protein VP1 genes and antibodies in 84 non-Ct controls and 206 Ct patients using an enzyme-linked immunoassay (ELISA), followed by verification with Western blot. None of the subjects were exposed to an antibiotic treatment or had a C. pneumoniae infection. The VP1 antibody test was positive in both, the ELISA and Western blot assay, in 4 Ct patients. PCR amplification experiments revealed presence of the VP1 gene in 5 Ct patients. The results suggest that Chlamydia phage capsid protein VP1 may exist in some Ct patients.

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