Although classical type II secretion systems (T2SSs) are widely present in Gram-negative bacteria, atypical T2SSs can be found in some species. In Pseudomonas aeruginosa, in addition to the classical T2SS Xcp, it was reported that two genes, xphA and xqhA, located outside the xcp locus were organized in an operon (PaQa) which encodes the orphan PaQa subunit. This subunit is able to associate with other components of the classical Xcp machinery to form a functional hybrid T2SS.
View Article and Find Full Text PDFSecretins are an unusual and important class of bacterial outer membrane (OM) proteins. They are involved in the transport of single proteins or macromolecular structures such as pili, needle complexes, and bacteriophages across the OM. Secretins are multimeric ring-shaped structures that form large pores in the OM.
View Article and Find Full Text PDFPseudomonas aeruginosa is an opportunistic pathogen involved in several diseases, including cystic fibrosis and nosocomial infections. Although the behavior of this bacterium at 37 degrees C has been intensively studied, little is known about its capacity to adapt and survive at suboptimal temperatures, such as those encountered in hospitals. In this work, transcriptomic and proteomic analyses were used to identify factors that allow P.
View Article and Find Full Text PDFThe opportunistic human pathogen bacterium Pseudomonas aeruginosa secretes various exoproteins in its surrounding environment. Protein secretion involves different secretory systems, including the type II secretion system, or T2SS, that is one of the most efficient secretory pathways of P. aeruginosa.
View Article and Find Full Text PDFFEMS Microbiol Lett
November 2005
In Gram-negative bacteria, most of the sec-dependent exoproteins are secreted via the type II secretion system (T2SS or secreton). In Pseudomonas aeruginosa, T2SS consists of 12 Xcp proteins (XcpA and XcpP to XcpZ) organized as a multiproteic complex within the envelope. In this study, by a co-purification approach using a His-tagged XcpZ as a bait, XcpY and XcpZ were found associated together to constitute the most stable functional unit so far isolated from the P.
View Article and Find Full Text PDFRes Microbiol
September 2005
In gram-negative bacteria, most signal-peptide-dependent exoproteins are secreted via the type II secretion system (T2SS or secreton). In Pseudomonas aeruginosa, T2SS consists of twelve Xcp proteins (XcpA and XcpP to XcpZ) thought to be organized as a multiproteic complex within the envelope. Although well conserved, T2SS are known to be species-specific, namely for distant organisms, and this characteristic was thought to involve XcpP.
View Article and Find Full Text PDFThe human opportunistic pathogen Serratia marcescens is a bacterium with a broad host range, and represents a growing problem for public health. Serratia marcescens kills Caenorhabditis elegans after colonizing the nematode's intestine. We used C.
View Article and Find Full Text PDFGram-negative bacteria have evolved several types of secretion mechanisms to release proteins into the extracellular medium. One such mechanism, the type II secretory system, is a widely conserved two-step process. The first step is the translocation of signal peptide-bearing exoproteins across the inner membrane.
View Article and Find Full Text PDFMost of the exoproteins secreted by Pseudomonas aeruginosa are transported via the type II secretion system. This machinery, which is widely conserved in gram-negative bacteria, consists of 12 Xcp proteins organized as a multiprotein complex, also called the secreton. We previously reported that the mutual stabilization of XcpZ and XcpY plays an important role in the assembly of the secreton.
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