Browse
Submit Data
Databases
API
Help

Dataset Information

10 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Cys-Cys cross-linking shows contact between the N-terminus of lethal factor and Phe427 of the anthrax toxin pore.

ABSTRACT: Electrophysiological studies of wild-type and mutated forms of anthrax protective antigen (PA) suggest that the Phe clamp, a structure formed by the Phe427 residues within the lumen of the oligomeric PA pore, binds the unstructured N-terminus of the lethal factor and the edema factor during initiation of translocation. We now show by electrophysiological measurements and gel shift assays that a single Cys introduced into the Phe clamp can form a disulfide bond with a Cys placed at the N-terminus of the isolated N-terminal domain of LF. These results demonstrate direct contact of these Cys residues, supporting a model in which the interaction of the unstructured N-terminus of the translocated moieties with the Phe clamp initiates N- to C-terminal threading of these moieties through the pore.

SUBMITTER: Janowiak BE

PROVIDER: S-EPMC3082969 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Cys-Cys cross-linking shows contact between the N-terminus of lethal factor and Phe427 of the anthrax toxin pore.

Janowiak Blythe E BE Jennings-Antipov Laura D LD Collier R John RJ

Biochemistry 20110406 17

Electrophysiological studies of wild-type and mutated forms of anthrax protective antigen (PA) suggest that the Phe clamp, a structure formed by the Phe427 residues within the lumen of the oligomeric PA pore, binds the unstructured N-terminus of the lethal factor and the edema factor during initiation of translocation. We now show by electrophysiological measurements and gel shift assays that a single Cys introduced into the Phe clamp can form a disulfide bond with a Cys placed at the N-terminus ...[more]

PMID: 21425869

Similar Datasets

Assembly of anthrax toxin pore: lethal-factor complexes into lipid nanodiscs.

Project description:We have devised a procedure to incorporate the anthrax protective antigen (PA) pore complexed with the N-terminal domain of anthrax lethal factor (LFN ) into lipid nanodiscs and analyzed the resulting complexes by negative-stain electron microscopy. Insertion into nanodiscs was performed without relying on primary and secondary detergent screens. The preparations were relatively pure, and the percentage of PA pore inserted into nanodiscs on EM grids was high (∼43%). Three-dimensional analysis of negatively stained single particles revealed the LFN -PA nanodisc complex mirroring the previous unliganded PA pore nanodisc structure, but with additional protein density consistent with multiple bound LFN molecules on the PA cap region. The assembly procedure will facilitate collection of higher resolution cryo-EM LFN -PA nanodisc structures and use of advanced automated particle selection methods.

| S-EPMC3610055 | biostudies-literature

Onset of anthrax toxin pore formation.

Project description:Protective antigen (PA) is the anthrax toxin protein recognized by capillary morphogenesis gene 2 (CMG2), a transmembrane cellular receptor. Upon activation, seven ligand-receptor units self-assemble into a heptameric ring-like complex that becomes endocytozed by the host cell. A critical step in the subsequent intoxication process is the formation and insertion of a pore into the endosome membrane by PA. The pore conversion requires a change in binding between PA and its receptor in the acidified endosome environment. Molecular dynamics simulations totaling approximately 136 ns on systems of over 92,000 atoms were performed. The simulations revealed how the PA-CMG2 complex, stable at neutral conditions, becomes transformed at low pH upon protonation of His-121 and Glu-122, two conserved amino acids of the receptor. The protonation disrupts a salt bridge important for the binding stability and leads to the detachment of PA domain II, which weakens the stability of the PA-CMG2 complex significantly, and subsequently releases a PA segment needed for pore formation. The simulations also explain the great strength of the PA-CMG2 complex achieves through extraordinary coordination of a divalent cation.

| S-EPMC1432108 | biostudies-literature

Asymmetric Cryo-EM Structure of Anthrax Toxin Protective Antigen Pore with Lethal Factor N-Terminal Domain.

Project description:The anthrax lethal toxin consists of protective antigen (PA) and lethal factor (LF). Understanding both the PA pore formation and LF translocation through the PA pore is crucial to mitigating and perhaps preventing anthrax disease. To better understand the interactions of the LF-PA engagement complex, the structure of the LFN-bound PA pore solubilized by a lipid nanodisc was examined using cryo-EM. CryoSPARC was used to rapidly sort particle populations of a heterogeneous sample preparation without imposing symmetry, resulting in a refined 17 Å PA pore structure with 3 LFN bound. At pH 7.5, the contributions from the three unstructured LFN lysine-rich tail regions do not occlude the Phe clamp opening. The open Phe clamp suggests that, in this translocation-compromised pH environment, the lysine-rich tails remain flexible and do not interact with the pore lumen region.

| S-EPMC5666345 | biostudies-literature

Roles of Anthrax Toxin Receptor 2 in Anthrax Toxin Membrane Insertion and Pore Formation.

Project description:Interaction between bacterial toxins and cellular surface receptors is an important component of the host-pathogen interaction. Anthrax toxin protective antigen (PA) binds to the cell surface receptor, enters the cell through receptor-mediated endocytosis, and forms a pore on the endosomal membrane that translocates toxin enzymes into the cytosol of the host cell. As the major receptor for anthrax toxin in vivo, anthrax toxin receptor 2 (ANTXR2) plays an essential role in anthrax toxin action by providing the toxin with a high-affinity binding anchor on the cell membrane and a path of entry into the host cell. ANTXR2 also acts as a molecular clamp by shifting the pH threshold of PA pore formation to a more acidic pH range, which prevents premature pore formation at neutral pH before the toxin reaches the designated intracellular location. Most recent studies have suggested that the disulfide bond in the immunoglobulin (Ig)-like domain of ANTXR2 plays an essential role in anthrax toxin action. Here we will review the roles of ANTXR2 in anthrax toxin action, with an emphasis on newly updated knowledge.

| S-EPMC4773787 | biostudies-literature

Cryo-EM structure of the fully-loaded asymmetric anthrax lethal toxin in its heptameric pre-pore state.

Project description:Anthrax toxin is the major virulence factor secreted by Bacillus anthracis, causing high mortality in humans and other mammals. It consists of a membrane translocase, known as protective antigen (PA), that catalyzes the unfolding of its cytotoxic substrates lethal factor (LF) and edema factor (EF), followed by translocation into the host cell. Substrate recruitment to the heptameric PA pre-pore and subsequent translocation, however, are not well understood. Here, we report three high-resolution cryo-EM structures of the fully-loaded anthrax lethal toxin in its heptameric pre-pore state, which differ in the position and conformation of LFs. The structures reveal that three LFs interact with the heptameric PA and upon binding change their conformation to form a continuous chain of head-to-tail interactions. As a result of the underlying symmetry mismatch, one LF binding site in PA remains unoccupied. Whereas one LF directly interacts with a part of PA called α-clamp, the others do not interact with this region, indicating an intermediate state between toxin assembly and translocation. Interestingly, the interaction of the N-terminal domain with the α-clamp correlates with a higher flexibility in the C-terminal domain of the protein. Based on our data, we propose a model for toxin assembly, in which the relative position of the N-terminal α-helices in the three LFs determines which factor is translocated first.

| S-EPMC7462287 | biostudies-literature

Anthrax toxin receptor 2-dependent lethal toxin killing in vivo.

Project description:Anthrax toxin receptors 1 and 2 (ANTXR1 and ANTXR2) have a related integrin-like inserted (I) domain which interacts with a metal cation that is coordinated by residue D683 of the protective antigen (PA) subunit of anthrax toxin. The receptor-bound metal ion and PA residue D683 are critical for ANTXR1-PA binding. Since PA can bind to ANTXR2 with reduced affinity in the absence of metal ions, we reasoned that D683 mutant forms of PA might specifically interact with ANTXR2. We show here that this is the case. The differential ability of ANTXR1 and ANTXR2 to bind D683 mutant PA proteins was mapped to nonconserved receptor residues at the binding interface with PA domain 2. Moreover, a D683K mutant form of PA that bound specifically to human and rat ANTXR2 mediated killing of rats by anthrax lethal toxin, providing strong evidence for the physiological importance of ANTXR2 in anthrax disease pathogenesis.

| S-EPMC1617126 | biostudies-literature

Small molecule inhibitors of anthrax lethal factor toxin.

Project description:This manuscript describes the preparation of new small molecule inhibitors of Bacillus anthracis lethal factor. Our starting point was the symmetrical, bis-quinolinyl compound 1 (NSC 12155). Optimization of one half of this molecule led to new LF inhibitors that were desymmetrized to afford more drug-like compounds.

| S-EPMC3925373 | biostudies-literature

Anthrax Lethal Toxin-Inducd Gene Expression Changes in Mouse Lung

Project description:Enhanced susceptibility of A/J mice to death by systemic anthrax lethal toxin (LeTx) administration compared to the C57BL/6 strain was observed. In this study we investigated whether systemic exposure of mice to LeTx would induce gene expression changes associated with vascular/capillary leakage in lung tissue. Lungs of the less susceptible C57BL/6 strain showed 80% fewer differentially expressed genes compared to lungs of the more sensitive A/J strain.

2011-09-07 | GSE28554 | GEO

Anthrax Lethal Toxin-Inducd Gene Expression Changes in Mouse Lung

2011-09-06 | E-GEOD-28554 | biostudies-arrayexpress

Suppressive effects of anthrax lethal toxin on megakaryopoiesis.

Project description:Anthrax lethal toxin (LT) is a major virulence factor of Bacillus anthracis. LT challenge suppresses platelet counts and platelet function in mice, however, the mechanism responsible for thrombocytopenia remains unclear. LT inhibits cellular mitogen-activated protein kinases (MAPKs), which are vital pathways responsible for cell survival, differentiation, and maturation. One of the MAPKs, the MEK1/2-extracellular signal-regulated kinase pathway, is particularly important in megakaryopoiesis. This study evaluates the hypothesis that LT may suppress the progenitor cells of platelets, thereby inducing thrombocytopenic responses. Using cord blood-derived CD34(+) cells and mouse bone marrow mononuclear cells to perform in vitro differentiation, this work shows that LT suppresses megakaryopoiesis by reducing the survival of megakaryocytes. Thrombopoietin treatments can reduce thrombocytopenia, megakaryocytic suppression, and the quick onset of lethality in LT-challenged mice. These results suggest that megakaryocytic suppression is one of the mechanisms by which LT induces thrombocytopenia. These findings may provide new insights for developing feasible approaches against anthrax.

| S-EPMC3605335 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data