Search results for "Plasmids"
showing 10 items of 209 documents
Fitness drift of an atrazine-degrading population under atrazine selection pressure.
2008
International audience; Pseudomonas sp. ADP harbouring the atrazine catabolic plasmid ADP1 was subcultured in liquid medium containing atrazine as sole source of nitrogen. After approximately 320 generations, a new population evolved which replaced the initial population. This newly evolved population grew faster and degraded atrazine more rapidly than the initial population. Plasmid profiles and Southern blot analyses revealed that the evolved strain, unlike the ancestral strain, presented a tandem duplication of the atzB gene encoding the second enzyme of the atrazine catabolic pathway responsible for the transformation of hydroxyatrazine to N-isopropylammelide. This duplication resulted …
Molecular relationship among Salmonella dublin isolates identified at the Center for Enterobacteriaceae of Palermo during the years 1971-85.
1987
SUMMARYA molecular epidemiological study was carried out on 60Salmonella dublinisolates identified at the Southern Italy Enterobacteriaceae Center between 1971 and 1985. These included 23 isolates from children with diarrhoea in Palermo obtained during 1984.All isolates from the outbreak of gastroenteritis in children were resistant to chloramphenicol and streptomycin and harboured two plasmids of 50 MDa and 3 MDa molecular weight, whereas the majority of the isolates identified before 1984 were susceptible to these antibiotics and carried only a 50 MDa molecular weight plasmid. FourS. dublinstrains successively identified from cattle (Palermo, Foggia, Portici) and from a child (Palermo) we…
Mononuclear Perfluoroalkyl-Heterocyclic Complexes of Pd(II): Synthesis, Structural Characterization and Antimicrobial Activity
2020
Two mononuclear Pd(II) complexes [PdCl2(pfptp)] (1) and [PdCl2(pfhtp)] (2), with ligands 2-(3-perfluoropropyl-1-methyl-1,2,4-triazole-5yl)-pyridine (pfptp) and 2-(3-perfluoroheptyl-1-methyl-1,2,4-triazole-5yl)-pyridine (pfhtp), were synthesized and structurally characterized. The two complexes showed a bidentate coordination of the ligand occurring through N atom of pyridine ring and N4 atom of 1,2,4-triazole. Both complexes showed antimicrobial activity when tested against both Gram-negative and Gram-positive bacterial strains.
Recombinant cDNA encapsulation in small liposomes with hepatocyte access ability.
1993
Liposomal encapsulation efficiency of a recombinant cDNA was studied by several procedures. We observed that supernatant fraction of ultracentrifuged liposomes prepared by extrusion through polycarbonate filters of 400 nm pore size yielded a very homogeneous suspension of small (50 nm diameter) unilamellar liposomes with highest DNA/lipid ratio and great ability to access to hepatocytes.
Multiple copies of SUC4 regulatory regions may cause partial de-repression of invertase synthesis in Saccharomyces cerevisiae.
1992
Transformation to generate multiple copies of regulatory DNA sequences has been used to study the interactions between regulatory proteins and their target sequences, since a high copy number of these sequences may titrate trans-acting regulatory proteins. We have analyzed the synthesis of invertase in yeast strains carrying different SUC genes transformed with the multiple-copy plasmid pSH143, a derivative of pJDB207 containing the promoter and upstream regulatory sequences of SUC4. The results obtained seem to be strain dependent. Under repressing conditions a high copy number of SUC4 promoter regions may cause increased expression of the invertase genes resulting in the synthesis of exte…
Overexpression of the truncated form of high mobility group a proteins (HMGA2) in human myometrial cells induces leiomyoma-like tissue formation
2014
The pathogenesis of uterine leiomyomas, the most common benign tumor in women, is still unknown. This lack of basic knowledge limits the development of novel non-invasive therapies. Our group has previously demonstrated that leiomyoma side population (SP) cells are present in tumor lesions and act like putative tumor-initiating stemcells in human leiomyoma. Moreover, accumulated evidence demonstrates that these benign tumors of mesenchymal origin are characterized by rearrangements of the High Mobility Group A proteins (HMGA). In this work, we tested the hypothesis that leiomyoma development may be due to overexpression of HMGA2 (encoding high mobility group AT-hook2) in myometrial stem cel…
Lipase maturation factor 1 is required for endothelial lipase activity
2011
Lipase maturation factor 1 (Lmf1) is an endoplasmic reticulum (ER) membrane protein involved in the posttranslational folding and/or assembly of lipoprotein lipase (LPL) and hepatic lipase (HL) into active enzymes. Mutations in Lmf1 are associated with diminished LPL and HL activities ("combined lipase deficiency") and result in severe hypertriglyceridemia in mice as well as in human subjects. Here, we investigate whether endothelial lipase (EL) also requires Lmf1 to attain enzymatic activity. We demonstrate that cells harboring a (cld) loss-of-function mutation in the Lmf1 gene are unable to generate active EL, but they regain this capacity after reconstitution with the Lmf1 wild type. Fur…
Avidin Is a Promising Tag for Fusion Proteins Produced in Baculovirus-Infected Insect Cells
1999
The baculovirus expression vector system (BEVS) has become one of the most versatile and powerful eukaryotic systems for recombinant protein expression. We have constructed a novel baculovirus transfer vector (pbacAVs+C) which allows for the efficient production, detection, and single-step purification of the desired molecule as a secretion-compatible avidin fusion protein in insect cells. It also enables fast construction of the baculoviruses by site-specific transposition in Escherichia coli. To demonstrate the power of this vector, we report here on the production of immunologically intact hevein, a major cysteine-rich latex allergen, as avidin fusion protein. Our results indicate that a…
Further development of the β-lactamase MutaGen assay and evaluation by comparison with Ames fluctuation tests and theumu test
2005
A rapid, high-throughput bacterial mutagenicity test system has been developed (MutaGen test) that detects reversions of inactivating base-pair substitutions and frameshifts in a TEM-1 class A β-lactamase (ampicillinase) gene. To quickly and sensitively detect mutagens, the system utilises a series of plasmids that contain the mutated ampicillinase gene and the mucAB operon. Inactivating mutations in the ampicillinase gene include frameshifts integrated into repetitive GC-sequences and G-runs known to be mutagenic hot-spots, and base-pair substitutions inserted in or around the β-lactamase active site. Frameshift mutations completely inactivated the enzyme only when located downstream of th…
Photobacterium damselae subsp. damselae Major Virulence Factors Dly, Plasmid-Encoded HlyA, and Chromosome-Encoded HlyA Are Secreted via the Type II S…
2015
ABSTRACT Photobacterium damselae subsp. damselae is a marine bacterium that causes septicemia in marine animals and in humans. Previously, we had determined a major role of pPHDD1 plasmid-encoded Dly (damselysin) and HlyA (HlyA pl ) and the chromosome-encoded HlyA (HlyA ch ) hemolysins in virulence. However, the mechanisms by which these toxins are secreted remain unknown. In this study, we found that a mini-Tn 10 transposon mutant in a plasmidless strain showing an impaired hemolytic phenotype contained an insertion in epsL , a component of a type II secretion system (T2SS). Reconstruction of the mutant by allelic exchange confirmed the specific involvement of epsL in HlyA ch secretion. In…