A novel human antimicrobial factor targets Pseudomonas aeruginosa through its type III secretion system

Mahmood, Fareeha; Hakimiyan, Arnavaz; Jayaraman, Vijayakumar; Wood, Stephen; Sivaramakrishnan, Gayathri; Rehman, Tooba; Reuhs, Bradley L.; Chubinskaya, S.; Shafikhani, Sasha H.

doi:10.1099/jmm.0.051227-0

Cited by 12 publications

(10 citation statements)

References 62 publications

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“…Lactoferrin, part of the human innate defense, proteolytically cleaves the EPEC translocator protein EspB and prevents T3S [96]. Recently, a secreted component of human cartilage was identified that was toxic to P. aeruginosa but not to an otherwise identical strain lacking the T3SS [97].…”

Section: Compounds In the Human Bodymentioning

confidence: 99%

Targeting the type III secretion system to treat bacterial infections

Marshall

Finlay

2013

Expert Opinion on Therapeutic Targets

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Section: Compounds In the Human Bodymentioning

confidence: 99%

Targeting the type III secretion system to treat bacterial infections

Marshall

Finlay

2013

Expert Opinion on Therapeutic Targets

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“…The complexation of ExoT to SpcS monomers results in burial of a large surface area (3969. 2 A 2 ) at the interface, with a slight difference in individual complexation, the MBD subunit (1399 A 2 ) being slightly larger than the CBD subunit (862. 8 A 2 ).…”

Section: Exot-spcs Complexmentioning

confidence: 98%

Interfacial residues of SpcS chaperone affects binding of effector toxin ExoT in Pseudomonas aeruginosa: novel insights from structural and computational studies

Dey

Datta

2014

The FEBS Journal

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ExoT belongs to the family of type 3 secretion system (T3SS) effector toxins in Pseudomonas aeruginosa, known to be one of the major virulence determinant toxins that cause chronic and acute infections in immuno‐compromised individuals, burn victims and cystic fibrosis patients. Here, we report the X‐ray crystal structure of the amino terminal fragment of effector toxin ExoT, in complex with full‐length homodimeric chaperone SpcS at 2.1 Å resolution. The full‐length dimeric chaperone SpcS has the conserved α‐β‐β‐β‐α‐β‐β‐α fold of class I chaperones, the characteristic hydrophobic patches for binding effector proteins and a conserved polar cavity at the dimeric interface. The stable crystallized amino terminal fragment of ExoT consists of a chaperone binding domain and a membrane localization domain that wraps around the dimeric chaperone. Site‐directed mutagenesis experiments and a molecular dynamics study complement each other in revealing Asn65, Phe67 and Trp88 as critical dimeric interfacial residues that can strongly influence the effector–chaperone interactions. Database The atomic coordinates and structure factors of ExoT–SpcS complex (code http://www.rcsb.org/pdb/search/structidSearch.do?structureId=4JMF) have been deposited in the Protein Data Bank Japan (PDBj), Institute for Protein Research, Osaka University.

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“…The bacterial strains used in these studies were an ExoT-expressing ExoU-deleted PA103 strain (DU) or its isogenic ExoT-defective type III secretion system (T3SS) mutant strain [PA103 pscJ-gent R (pscJ)]. These strains were described previously (Shafikhani & Engel, 2006;Shafikhani et al, 2008;Mahmood et al, 2013). Cancer cells, infected with ExoT-expressing and ExoT-defective P. aeruginosa, were placed under 5 % CO 2 at 37 uC in an incubation chamber (Pecon) fitted to an AxioVert Z1 (Zeiss) microscope using AxioVision version 4.2 software.…”

Section: Methodsmentioning

confidence: 99%

“…In a 24-well plate, cancer cells were seeded at 8610 4 cells per well and cultured in 1 ml DMEM (Gibco) media without phenol red, sodium pyruvate and penicillin/ streptomycin antibiotics, and supplemented with 1 % FBS. To further assess the cytotoxic effect ExoT had on cancer, tumour cell lines were infected with either ExoT-expressing ExoU-deleted PA103 strain (DU) or its isogenic ExoT-defective T3SS mutant strain (pscJ) at m.o.i.~10 (Shafikhani & Engel, 2006;Shafikhani et al, 2008;Mahmood et al, 2013). To measure the amount of LDH release, the suspensions of uninfected and infected cells were collected and centrifuged at 2.5 g for 10 min to remove bacteria.…”

Section: Methodsmentioning

confidence: 99%