2003

2003. pilus gene clusters, in some types of pili, small pilin subunits may contribute to backbone formation by a novel mechanism. Pilus-like constructions on the surface of Gram-positive bacteria were first observed in by electron microscopy (50), and recently, these surface appendages have been characterized genetically and biochemically in many additional Gram-positive bacterial pathogens (18, 33, 44, 46). Gram-positive bacterial pili are anchored to the cell wall peptidoglycan and consist of covalently cross-linked subunit proteins (18, 33, 44, 46). Polymerized monomers of a single major pilin subunit form the pilus backbone, to which one or more small (or ancillary) pilin subunits are attached (18, 33, 44, 46). Both the major and small subunits contain C-terminal cell wall sorting signals (CWSSs), composed of a pentapeptide motif displayed by LPXTG (where X is definitely any amino acid), a C-terminal hydrophobic website, and a charged tail (32). The subunits are put together via CWSSs from the action of pilus-specific class C sortases (8). Major pilin subunits have been shown to be indispensable for pilus formation. In contrast, early studies showed that small subunits are not essential for pilus synthesis and assembly (10, 39, 47). It has only recently been reported that small pilin subunits of SpaA- and SpaH-type pili of and Spy0130 (FctB) of a serotype M1 strain participate in the termination of pilus polymerization as well as with anchoring the polymer to the cell wall peptidoglycan (17, 35). However, in many Gram-positive bacterial pili, the tasks of small pilin subunits in pilus formation remain to be fully elucidated. is definitely a Gram-positive coccus responsible for a wide range of diseases in pigs, including meningitis, septicemia, endocarditis, and sudden death (14, DSP-2230 37). This bacterium can also impact humans in close contact with diseased pigs or swine products (1, 7, 43, 49, 51). Four putative pilus gene clusters, named the clusters, have so far been recognized in (9, 40). The cluster, recognized in strain 89/1591, consists of one putative sortase gene, and (Fig. ?(Fig.1A).1A). The genetic organization of the cluster was related to that of the fibronectin-binding, collagen-binding, T-antigen 1 (FCT-1) region of (21). Moreover, the amino acid sequences of SrtG, Sgp1, and Sgp2 showed 35 to 56% identity with those of the proteins encoded from the related genes for the FCT-1 region (40). However, despite the predictions, it is unfamiliar whether this cluster is definitely associated with the manifestation of pilus materials in pilus cluster. This schema is definitely constructed on the basis of the draft genome sequence of 89/1591, updated in February 2009 (GenBank accession no. “type”:”entrez-nucleotide”,”attrs”:”text”:”AAFA03000013″,”term_id”:”223898166″,”term_text”:”AAFA03000013″AAFA03000013). Gray arrows, genes encoding CWSS-containing proteins (and 89/1591 by both immunoblotting and immunogold electron microscopy (IEM). By building a series of isogenic mutant strains, we shown the cluster mediates pilus formation in 89/1591 and that the small subunit Sgp2 is necessary for polymerization of the major subunit Sgp1. MATERIALS AND METHODS Bacterial strains, plasmids, and tradition conditions. The bacterial strains and plasmids used in this study Cd19 are outlined in Table ?Table1.1. strains were cultivated in Todd-Hewitt (Becton Dickinson, Sparks, MD) broth (THB) or agar (THA) at 37C inside a 5% CO2 atmosphere, unless otherwise specified. strains were cultured DSP-2230 in Luria-Bertani (Becton Dickinson) broth or agar at 37C. When required, the following antibiotics were added to the medium in the indicated concentrations: for promoter of geneThis study????pSgp1pMX1 carrying intact geneThis study????pSgp2pMX1 carrying intact geneThis studystrains????89/1591Wild-type strain isolated from a pig with septicemia and meningitis30????(strains????TOP10Host for pCR2.1 and pSET4s derivativesInvitrogen????BL21(DE3)/pDIA17Host for pIVEX2.4d derivatives28????MC1061Host for pMX1 derivatives6 Open in a separate window DNA techniques. Restriction enzymes and DNA-modifying enzymes were purchased from Takara Bio (Otsu, Japan) and used according to the manufacturer’s recommendations. Purification of plasmid DNA from and transformation of were performed using standard methods (31). Genomic DNA of was extracted by the method explained previously (25), and was transformed by electroporation, as explained previously (41). Ex lover polymerase (Takara Bio) and iProof HF expert blend (Bio-Rad Laboratories, Hercules, CA) were utilized for PCR amplification. Primers used in this study are outlined in Table S1 in the supplemental material. Sequencing was carried out having a BigDye Terminator DSP-2230 (version 3.1) cycle sequencing kit (Applied Biosystems, Foster City, CA) and analyzed on a 3100 genetic analyzer or 3130xl genetic analyzer (Applied Biosystems). Generation of mutants. For the building of precise in-frame deletions in shuttle vector pSET4s (42). The producing plasmids were launched into 89/1591 by electroporation. The single-crossover mutant (CPS2B) and DSP-2230 double-crossover.