scholarly journals The Central Spike Complex of Bacteriophage T4 Contacts PpiD in the Periplasm of Escherichia coli

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1135
Author(s):  
Sabrina Wenzel ◽  
Mikhail M. Shneider ◽  
Petr G. Leiman ◽  
Andreas Kuhn ◽  
Dorothee Kiefer
Keyword(s):  
Escherichia Coli ◽  
Cytoplasmic Membrane ◽  
Bacteriophage T4 ◽  
Infection Process ◽  
Host Cells ◽  
Phage Dna ◽  
Tail Structure ◽  
Contractile Tail ◽  
Periplasmic Chaperone

Infecting bacteriophage T4 uses a contractile tail structure to breach the envelope of the Escherichia coli host cell. During contraction, the tail tube headed with the “central spike complex” is thought to mechanically puncture the outer membrane. We show here that a purified tip fragment of the central spike complex interacts with periplasmic chaperone PpiD, which is anchored to the cytoplasmic membrane. PpiD may be involved in the penetration of the inner membrane by the T4 injection machinery, resulting in a DNA-conducting channel to translocate the phage DNA into the interior of the cell. Host cells with the ppiD gene deleted showed partial reduction in the plating efficiency of T4, suggesting a supporting role of PpiD to improve the efficiency of the infection process.

scholarly journals Contribution of the FtsQ Transmembrane Segment to Localization to the Cell Division Site

2007 ◽  
Vol 189 (20) ◽  
pp. 7273-7280 ◽  
Author(s):  
Dirk-Jan Scheffers ◽  
Carine Robichon ◽  
Gert Jan Haan ◽  
Tanneke den Blaauwen ◽  
Gregory Koningstein ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Membrane Protein ◽  
Cytoplasmic Membrane ◽  
Central Component ◽  
Transmembrane Segment ◽  
Division Site ◽  
Periplasmic Domain ◽  
Cell Division Protein

ABSTRACT The Escherichia coli cell division protein FtsQ is a central component of the divisome. FtsQ is a bitopic membrane protein with a large C-terminal periplasmic domain. In this work we investigated the role of the transmembrane segment (TMS) that anchors FtsQ in the cytoplasmic membrane. A set of TMS mutants was made and analyzed for the ability to complement an ftsQ mutant. Study of the various steps involved in FtsQ biogenesis revealed that one mutant (L29/32R;V38P) failed to functionally insert into the membrane, whereas another mutant (L29/32R) was correctly assembled and interacted with FtsB and FtsL but failed to localize efficiently to the cell division site. Our results indicate that the FtsQ TMS plays a role in FtsQ localization to the division site.

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

1998 ◽  
Vol 180 (7) ◽  
pp. 1723-1728 ◽  
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.

scholarly journals Enteropathogenic Escherichia coli (EPEC) Tir Receptor Molecule Does Not Undergo Full Modification When Introduced into Host Cells by EPEC-Independent Mechanisms

2001 ◽  
Vol 69 (3) ◽  
pp. 1444-1453 ◽  
Author(s):  
Brendan Kenny ◽  
Jonathan Warawa
Keyword(s):  
Escherichia Coli ◽  
Molecular Mass ◽  
Type Iii Secretion ◽  
Efficiency Factor ◽  
Host Cells ◽  
Sufficient Information ◽  
Phosphorylation Event ◽  
Associated Proteins ◽  
Phosphate Groups

ABSTRACT Enteropathogenic Escherichia coli (EPEC), like many other gram-negative pathogens, encodes a type III secretion apparatus dedicated to the release of virulence-associated proteins. One such protein, Tir, is translocated into host cells, where it is modified by the addition of phosphate groups, resulting in a number of species with distinct molecular mass. One phosphorylation event, on tyrosine residue 474 of Tir, does not contribute to shifts in molecular mass but is essential for its actin-nucleating function. The role of the nonphosphotyrosine related modifications is unknown. In this paper, we demonstrate, using three different approaches, that Tir does not encode sufficient information to facilitate its complete modification when introduced into host cells in EPEC-independent mechanisms. Each system revealed that Tir is a substrate for a host kinase whose action results in its partial modification to a form similar to one evident in EPEC-infected host cells. Further Tir modification could not be induced by infecting cells with EPEC, suggesting that Tir must be coexpressed with other EPEC factors to enable its full modification within host cells. One approach usedYersinia spp. to deliver Tir into host cells, and this system revealed that Tir secretion and translocation can occur in the absence of the Tir chaperone molecule, CesT (formerly known as OrfU). CesT was found to be an efficiency factor which was not required, unlike in EPEC, for Tir stability, indicating that it may function to guide Tir to the translocation apparatus or maintain it in a secretion-competent form.

scholarly journals A First Model of the Dynamics of the Bacteriophage T4 Injection Machinery

2016 ◽  
Vol 11 (4) ◽  
Author(s):  
Ameneh Maghsoodi ◽  
Anupam Chatterjee ◽  
Ioan Andricioaei ◽  
N. C. Perkins
Keyword(s):  
Bacteriophage T4 ◽  
Infection Process ◽  
Hydrodynamic Drag ◽  
Kirchhoff Rod ◽  
Rod Theory ◽  
Tail Assembly ◽  
Contractile Tail ◽  
Helical Protein ◽  
Important Building Block ◽  
Sheath Structure

Bacteriophage T4 is one of the most common and complex of the tailed viruses that infect host bacteria using an intriguing contractile tail assembly. Despite extensive progress in resolving the structure of T4, the dynamics of the injection machinery remains largely unknown. This paper contributes a first model of the injection machinery that is driven by elastic energy stored in a structure known as the sheath. The sheath is composed of helical strands of protein that suddenly collapse from an energetic, extended conformation prior to infection to a relaxed, contracted conformation during infection. We employ Kirchhoff rod theory to simulate the nonlinear dynamics of a single protein strand coupled to a model for the remainder of the virus, including the coupled translation and rotation of the head (capsid), neck, and tail tube. Doing so provides an important building block toward the future goal of modeling the entire sheath structure which is composed of six interacting helical protein strands. The resulting numerical model exposes fundamental features of the injection machinery including the time scale and energetics of the infection process, the nonlinear conformational change experienced by the sheath, and the contribution of hydrodynamic drag on the head (capsid).

Phleomycin-stimulated solubilization of deoxyribonucleic acid in Escherichia coli. II. Inhibition of solubilization by bacteriophage T4

1976 ◽  
Vol 22 (5) ◽  
pp. 645-653 ◽  
Author(s):  
Larry D. Farrell ◽  
Harvard Reiter
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Deoxyribonucleic Acid ◽  
Cytoplasmic Membrane ◽  
Bacteriophage T4 ◽  
Continuous Exposure ◽  
Dna Endonuclease ◽  
Molecular Weights ◽  
Dependent Inhibition ◽  
Antibiotic Inhibition

Phleomycin-stimulated solubilization of Escherichia coli DNA is inhibited by infecting the cells with mutants of bacteriophage T4 before treatment with the antibiotic, inhibition requiring phage-specified protein synthesis. Two different modes of inhibition can be differentiated by infecting with mutants which are defective in an early state (gene den A−; endonuclease II-independent inhibition) or a late stage (gene 46−; endonuclease II-dependent inhibition) of phage-directed degradation of host DNA. Endonuclease II-independent inhibition results from interference with phleomycin-induced release of host DNA from the cytoplasmic membrane. In the presence of endonuclease II, the host DNA is converted to fragments, with average molecular weights of 106 daltons, the further degradation of which is not promoted by continuous exposure of the cells to phleomycin.

scholarly journals Characterization of the role of the Escherichia coli periplasmic chaperone SurA using differential proteomics

PROTEOMICS ◽  
2009 ◽  
Vol 9 (9) ◽  
pp. 2432-2443 ◽  
Author(s):  
Didier Vertommen ◽  
Natividad Ruiz ◽  
Pauline Leverrier ◽  
Thomas J. Silhavy ◽  
Jean-François Collet
Keyword(s):  
Escherichia Coli ◽  
Differential Proteomics ◽  
Periplasmic Chaperone
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