scholarly journals Pore-forming pyocin S5 utilizes the FptA ferripyochelin receptor to kill Pseudomonas aeruginosa

Microbiology ◽  
2014 ◽  
Vol 160 (2) ◽  
pp. 261-269 ◽  
Author(s):  
Ameer Elfarash ◽  
Jozef Dingemans ◽  
Lumeng Ye ◽  
Ahmed Amir Hassan ◽  
Michael Craggs ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Receptor Binding ◽  
Protein Product ◽  
Binding Domain ◽  
Burkholderia Cenocepacia ◽  
Receptor Binding Domain ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Siderophore Receptors ◽  
Transposon Mutants

Pyocins are toxic proteins produced by some strains of Pseudomonas aeruginosa that are lethal for related strains of the same species. Some soluble pyocins (S2, S3 and S4) were previously shown to use the pyoverdine siderophore receptors to enter the cell. The P. aeruginosa PAO1 pore-forming pyocin S5 encoding gene (PAO985) was cloned into the expression vector pET15b, and the affinity-purified protein product tested for its killing activity against different P. aeruginosa strains. The results, however, did not show any correlation with a specific ferripyoverdine receptor. To further identify the S5 receptor, transposon mutants were generated. Pooled mutants were exposed to pyocin S5 and the resistant colonies growing in the killing zone were selected. The majority of S5-resistant mutants had an insertion in the fptA gene encoding the receptor for the siderophore pyochelin. Complementation of an fptA transposon mutant with the P. aeruginosa fptA gene in trans restored the sensitivity to S5. In order to define the receptor-binding domain of pyocin S5, two hybrid pyocins were constructed containing different regions from pyocin S5 fused to the C-terminal translocation and DNase killing domains of pyocin S2. Only the protein containing amino acid residues 151 to 300 from S5 showed toxicity, indicating that the pyocin S5 receptor-binding domain is not at the N-terminus of the protein as in other S-type pyocins. Pyocin S5 was, however, unable to kill Burkholderia cenocepacia strains producing a ferripyochelin FptA receptor, nor was the B. cenocepacia fptA gene able to restore the sensitivity of the resistant fptA mutant P. aeruginosa strain.

ReaxFF-based molecular dynamics simulation of the interaction between plasma ROS and the receptor-binding domain of the spike protein in the capsid protein of SARS-CoV-2

2021 ◽  
Author(s):  
Huichao Wang ◽  
Tong Zhao ◽  
Shuhui Yang ◽  
Liang Zou ◽  
Xiaolong Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Amino Acid ◽  
Capsid Protein ◽  
Receptor Binding ◽  
Hydrogen Abstraction ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Amino Acid Residues ◽  
Global Epidemic

Abstract Under the severe situation of the current global epidemic, researchers have been working hard to find a reliable way to suppress the infection of the virus and prevent the spread of the epidemic. Studies have shown that the recognition and binding of human angiotensin-converting enzyme 2 (ACE2) by the receptor-binding domain (BRD) of spike protein on the surface of SARS-CoV-2 is a crucial step for SARS-CoV-2 to invade human receptor cells, and blocking this process can inhibit the virus from invading human normal cells. Plasma treatment can disrupt the structure of the RBD and effectively block the binding process. However, the mechanism by which plasma blocks the recognition and binding between the two is not clear. In this study, reaction process between reactive oxygen species (ROS) in plasma and the molecular model of RBD was simulated using a reactive molecular dynamics method. The results showed that the destruction of RBD molecule by ROS was triggered by hydrogen abstraction reactions. O and OH abstracted H atoms from RBD, while the H atoms of H2O2 and HO2 were abstracted by RBD. The hydrogen abstraction resulted in the breakage of C-H, N-H, O-H and C=O bonds and the formation of C=C, C=N bonds. The addition reaction of OH increased the number of O-H bonds and caused the formation of C-O, N-O and O-H bonds. The dissociation of N-H bonds led to the destruction of the original structure of peptide bonds and amino acid residues, change the type of amino acid residues, and caused the conversion of N-C and N=C, C=O and C-O. The simulation partially elucidated the microscopic mechanism of the interaction between ROS in plasma and the capsid protein of SARS-CoV-2, providing theoretical support for the control of SARS-CoV-2 infection by plasma, a contribution to overcoming the global epidemic problem.

scholarly journals Receptor Binding Domain of Escherichia coli F18 Fimbrial Adhesin FedF Can Be both Efficiently Secreted and Surface Displayed in a Functional Form in Lactococcus lactis

2004 ◽  
Vol 70 (4) ◽  
pp. 2061-2071 ◽  
Author(s):  
Agneta Lindholm ◽  
Andreas Smeds ◽  
Airi Palva
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Receptor Binding ◽  
Intestinal Epithelial Cells ◽  
Surface Display ◽  
Cell Surface Display ◽  
Binding Domain ◽  
Intestinal Epithelial ◽  
Receptor Binding Domain ◽  
Amino Acid Residues

ABSTRACT Adherence of F18 fimbrial Escherichia coli to porcine intestinal epithelial cells is mediated by the adhesin (FedF) of F18 fimbriae. In a previous study, we demonstrated the specificity of the amino acid residues between 60 and 109 as the receptor binding domain of FedF. In this study, different expression, secretion, and anchoring systems for the receptor binding domain of the FedF adhesin in Lactococcus lactis were evaluated. Two partially overlapping receptor binding domains (42 and 62 amino acid residues) were expressed as fusions with L. lactis subsp. cremoris protein PrtP for evaluation of secretion efficiency. To evaluate the cell surface display of these FedF-PrtP fusions, they were further combined with different lengths of PrtP spacers fused with either the L. lactis AcmA anchor or the PrtP cell wall binding domain. An HtrA-defective L. lactis NZ9000 mutant was constructed to determine its effect on the level of secreted or anchored fusion proteins. Recombinant L. lactis clones secreting the receptor binding domain of F18 fimbriae as a fusion with the H domains of L. lactis protein PrtP were first constructed by using two different signal peptides. FedF-PrtP fusions, directed by the signal sequence of L. brevis SlpA, were throughout found to be secreted at significantly higher quantities than corresponding fusions with the signal peptide of L. lactis Usp45. In the surface display systems tested, the L. lactis AcmA anchor performed significantly better, particularly in the L. lactis NZ9000ΔhtrA strain, compared to the L. lactis PrtP anchor region. Of the cell surface display constructs with the AcmA anchor, only those with the longest PrtP spacer regions resulted in efficient binding of recombinant L. lactis cells to porcine intestinal epithelial cells. These results confirmed that it is possible to efficiently produce the receptor binding domain of the F18 adhesin in a functionally active form in L. lactis.

The Pseudomonas aeruginosa type IV pilin receptor binding domain functions as an adhesin for both biotic and abiotic surfaces

2006 ◽  
Vol 60 (3) ◽  
pp. 813-813 ◽  
Author(s):  
Carmen L. Giltner ◽  
Erin J. van Schaik ◽  
Gerald F. Audette ◽  
Dan Kao ◽  
Robert S. Hodges ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Receptor Binding ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Type Iv ◽  
Abiotic Surfaces ◽  
Type Iv Pilin

scholarly journals Peptide inhibitors of the interaction of the SARS-CoV-2 receptor-binding domain with the ACE2 cell receptor

2021 ◽  
Vol 67 (3) ◽  
pp. 244-250
Author(s):  
R.Sh. Bibilashvili ◽  
M.V. Sidorova ◽  
U.S. Dudkina ◽  
M.E. Palkeeva ◽  
A.S. Molokoedov ◽  
...  
Keyword(s):  
Amino Acid ◽  
Receptor Binding ◽  
Disulfide Bonds ◽  
Protein S ◽  
Cell Receptor ◽  
Binding Domain ◽  
Amino Acid Sequences ◽  
Receptor Binding Domain ◽  
Amino Acid Residues ◽  
Chimeric Molecules

Computer simulation has been used to identify peptides that mimic the natural target of the SARS-CoV-2 coronavirus spike (S) protein, the angiotensin converting enzyme type 2 (ACE2) cell receptor. Based on the structure of the complex of the protein S receptor-binding domain (RBD) and ACE2, the design of chimeric molecules consisting of two 22-23-mer peptides linked to each other by disulfide bonds was carried out. The chimeric molecule X1 was a disulfide dimer, in which edge cysteine residues in the precursor molecules h1 and h2 were connected by the S-S bond. In the chimeric molecule X2, the disulfide bond was located in the middle of the molecule of each of the precursor peptides. The precursors h1 and h2 modelled amino acid sequences of α1- and α2-helices of the extracellular peptidase domain of ACE2, respectively, keeping intact most of the amino acid residues involved in the interaction with RBD. The aim of the work was to evaluate the binding efficiency of chimeric molecules and their RBD-peptides (particularly in dependence of the middle and edge methods of fixing the initial peptides h1 and h2). The proposed polypeptides and chimeric molecules were synthesized by chemical methods, purified (to 95-97% purity), and characterized by HPLC and MALDI-TOF mass spectrometry. The binding of the peptides to the SARS-CoV-2 RBD was evaluated by microthermophoresis with recombinant domains corresponding in sequence to the original Chinese (GenBank ID NC_045512.2) and the British (B. 1.1.7, GISAID EPI_ISL_683466) variants. Binding to the original RBD of the Chinese variant was detected in three synthesized peptides: linear h2 and both chimeric variants. Chimeric peptides were also bound to the RBD of the British variant with micromolar constants. The antiviral activity of the proposed peptides in Vero cell culture was also evaluated.

scholarly journals The Pseudomonas aeruginosa type IV pilin receptor binding domain functions as an adhesin for both biotic and abiotic surfaces

2006 ◽  
Vol 59 (4) ◽  
pp. 1083-1096 ◽  
Author(s):  
Carmen L. Giltner ◽  
Erin J. van Schaik ◽  
Gerald F. Audette ◽  
Dan Kao ◽  
Robert S. Hodges ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Receptor Binding ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Type Iv ◽  
Abiotic Surfaces ◽  
Type Iv Pilin

scholarly journals A Colicin M-Type Bacteriocin fromPseudomonas aeruginosaTargeting the HxuC Heme Receptor Requires a Novel Immunity Partner

2018 ◽  
Vol 84 (18) ◽  
Author(s):  
Maarten G. K. Ghequire ◽  
Başak Öztürk
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Membrane Protein ◽  
Receptor Binding ◽  
Binding Domain ◽  
Modular Organization ◽  
Receptor Binding Domain ◽  
Inner Membrane ◽  
Content Type ◽  
Transmembrane Topology ◽  
Inner Membrane Protein

ABSTRACTPyocins are bacteriocins secreted byPseudomonas aeruginosa, and they assist in the colonization of different niches. A major subset of these antibacterial proteins adopt a modular organization characteristic of polymorphic toxins. They include a receptor-binding domain, a segment enabling membrane passage, and a toxin module at the carboxy terminus, which eventually kills the target cells. To protect themselves from their own products, bacteriocin-producing strains express an immunity gene concomitantly with the bacteriocin. We show here that a pyocin equipped with a phylogenetically distinct ColM toxin domain, PaeM4, mediates antagonism against a large set ofP. aeruginosaisolates. Immunity to PaeM4 is provided by the inner membrane protein PmiC, which is equipped with a transmembrane topology not previously described for the ColM family. Given that strains lacking apmiCgene are killed by PaeM4, the presence of such an immunity partner likely is a key criterion for escaping cellular death mediated by PaeM4. The presence of a TonB box in PaeM4 and enhanced bacteriocin activity under iron-poor conditions strongly suggested the targeting of a TonB-dependent receptor. Evaluation of PaeM4 activities against TonB-dependent receptor knockout mutants inP. aeruginosaPAO1 revealed that the heme receptor HxuC (PA1302) serves as a PaeM4 target at the cellular surface. Because other ColM-type pyocins may target the ferrichrome receptor FiuA, our results illustrate the versatility in target recognition conferred by the polymorphic nature of ColM-type bacteriocins.IMPORTANCEThe antimicrobial armamentarium of a bacterium is a major asset for colonizing competitive environments. Bacteriocins comprise a subset of these compounds. Pyocins are an example of such antibacterial proteins produced byPseudomonas aeruginosa, killing otherP. aeruginosastrains. A large group of these molecules show a modular protein architecture that includes a receptor-binding domain for initial target cell attachment and a killer domain. In this study, we have shown that a novel modular pyocin (PaeM4) that kills target bacteria via interference with peptidoglycan assembly takes advantage of the HxuC heme receptor. Cells can protect themselves from killing by the presence of a dedicated immunity partner, an integral inner membrane protein that adopts a transmembrane topology distinct from that of proteins currently known to provide immunity against such toxin activity. Understanding the receptors with which pyocins interact and how immunity to pyocins is achieved is a pivotal step toward the rational design of bacteriocin cocktails for the treatment ofP. aeruginosainfections.

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