Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.30.2 (endonuclease)
18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Imipenem sensitive pretherapy isolates (MICs 1-2 mg/l) and the corresponding resistant posttherapy isolates (MICs 16 mg/l) of Pseudomonas aeruginosa from three patients undergoing imipenem treatment were analyzed to establish the resistance mechanism. The identity of pyocin types, serotypes, DNA restriction endonuclease profiles and plasmid profiles strongly suggested isogenicity of pre- and posttherapy isolates. The imipenem resistant posttherapy isolates showed cross-resistance only to another carbapenem, meropenem. There were neither qualitative nor quantitative differences between pre- and posttherapy isolates in beta-lactamase production. Affinity of the penicillin-binding proteins 1A, 1B, 2, 3, 4,4' and 5 for [14C]imipenem was the same in pre- and posttherapy isolates. One-dimensional and two-dimensional gel electrophoresis of outer membrane protein preparations showed diminished expression of an outer membrane protein of about 46.5 and 47.5 kilodaltons, respectively, in the posttherapy isolates. This protein had an apparent isoelectric point of about pH 5.2 in two-dimensional gel electrophoresis. Growth in proteose peptone no. 2 broth did not reduce expression of this outer membrane protein, which spoke against its identity with the outer membrane protein D1. The permeability of the outer membrane for imipenem was reduced in the posttherapy isolates, since addition of 0.5 or 0.25 of the MIC of the permeabilizing agent ethylene-diaminetetraacetate reduced the MICs of imipenem for all isolates from each patient to the same (susceptible) level. The diminished expression of one of the outer membrane proteins might be the reason for this reduced permeability.
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PMID:Mechanism of imipenem resistance acquired by three Pseudomonas aeruginosa strains during imipenem therapy. 212 59

Several lines of evidence were obtained that the previously identified, repeated sequence RS1100 of Pseudomonas cepacia strain AC1100 undergoes transposition events. DNA sequences flanking the chlorohydroxy hydroquinone (CHQ) degradative genes of this organism were examined from sources, including several independently isolated cosmid clones from an AC1100 genomic library and genomic DNAs of two independently maintained wild-type AC1100 isolates. Hybridization and restriction endonuclease mapping studies revealed these sequences to be similar except for their numbers and distributions of RS1100 copies. A recombinant plasmid containing the immediate chq gene region and excluding any copies of RS1100 was conjugated into AC1100 mutant RHA5 which was shown to have undergone a deletion of its corresponding DNA. Hybridization and restriction mapping analyses of several reisolated plasmids revealed the presence of RS1100 sequences at different positions within either the vector or insert portions. One such plasmid contained tandem copies of RS1100 with an intervening DNA sequence also of AC1100 origin. Similar experiments involving introduction of the promoter probe plasmid pKT240 into wild-type AC1100 cells resulted in the acquisition of high-concentration streptomycin resistance by a number of recipients. The reisolated plasmids in most cases also conferred streptomycin resistance to Escherichia coli transformants and in each case were found to contain insertions close to the upstream portion of the aphC structural gene. These insertions alternatively contained RS1100 sequences for a newly identified 3400 bp repeated sequence from AC1100. Based on these results, RS1100 has been redesignated as insertion sequence IS931 and the 3400 bp repeated sequence has been designated as IS932.
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PMID:Repeated sequences including RS1100 from Pseudomonas cepacia AC1100 function as IS elements. 215 51

A restriction endonuclease map was derived for the aromatic amine and m-toluate catabolic plasmid pTDN1 present in Pseudomonas putida UCC22, a derivative of P. putida mt-2. The plasmid is 79 +/- 1 kbp in size and can be divided into a restriction-site-deficient region of 51 +/- 1 kbp and a restriction-site-profuse region of 28 kbp which begins and ends with directly repeating sequences of at least 2 kbp in length. A mutant plasmid isolated after growth of the host on benzoate had lost the restriction-profuse region by a straightforward recombinational loss retaining one copy of the direct repeat. Analysis of clones, deletion and Tn5 insertion mutants strongly suggested that the meta-cleavage pathway of pTDN1 was situated in the region readily deleted. The catechol 2,3-dioxygenase (C23O) gene of pTDN1 showed no hybridization or restriction homology to previously described C23O genes of TOL plasmids pWW0 and pWW15. In addition, there was little homology between intact pTDN1, pWW0 and pWW15, suggesting the presence of a unique meta-cleavage pathway. We also demonstrated that pTDN1 did not originate from P. putida mt-2 chromosome.
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PMID:Physical map of the aromatic amine and m-toluate catabolic plasmid pTDN1 in Pseudomonas putida: location of a unique meta-cleavage pathway. 216 27

The genes of Pseudomonas testosteroni strain B-356, specifying the transformation of 4-chlorobiphenyl (4-CB) into 4-chlorobenzoic acid (4-CBA) were cloned into Pseudomonas putida KT2440 using a broad-host-range cosmid, pPSA842. Of 10,000 clones tested, four were able to transform 4-CB. Gas chromatographic and mass spectrometric analysis of the catabolic products from two of the 4-CB-transforming clones carrying the hybrid plasmids, pDA1 and pDA2, demonstrated that pDA1 carried a complete set of structural genes involved in the transformation of 4-CB into 4-CBA, while pDA2 contained part of the pathway genes leading up to the meta-cleavage compound. Restriction endonuclease mapping and subcloning of pDA1 and pDA2 showed that the clones contained a common stretch of DNA of about 9.1 kb and that pDA2 carried gene(s) involved in regulation. Probing blots of genomic DNA from 13 different polychlorinated biphenyl(PCB)-degrading bacteria with radio-labelled pDA1 and pDA2, suggested that many PCB-degrading pathways have a common phylogenetic origin.
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PMID:Cloning and expression of genes involved in 4-chlorobiphenyl transformation by Pseudomonas testosteroni: homology to polychlorobiphenyl-degrading genes in other bacteria. 231 36

A Pseudomonas aeruginosa bacteriophage, phi PLS743, with extremely limited host range has been isolated. It belongs to the virus family Podoviridae, morphological type C1, and possesses a head diameter of 45 nm. The phage has a buoyant density in CsCl of 1.516 g/cm3, and its mass is 45 x 10(6) daltons. The phage particles are composed of double-stranded DNA (49.9 mol% G + C; 42.4 kilobase pairs) and 11 structural proteins (66% by weight). The major head protein, P5, has a Mr of 34,500. The DNA is not cut by SalI or XhoI restriction endonucleases, but is cut by PvuII (1 site), KpnI and BglII (2 sites), PvuI (4 sites), BamHI (7 sites), EcoRI (9 sites), and HindIII (12 sites). A restriction endonuclease map is presented.
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PMID:Isolation and characterization of a Pseudomonas aeruginosa bacteriophage with a very limited host range. 250 71

Nosocomial Pseudomonas aeruginosa isolates were typed by DNA fingerprinting techniques. Chromosomal DNA banding patterns, after endonuclease digestion, of six isolates from a neonatal care unit confirmed the results of O-serotyping and antimicrobial susceptibility pattern analysis. In contrast, the characterization by chromosomal DNA fingerprinting of P. aeruginosa strains isolated from patients treated in a burn unit disagreed with the two classic typing methods: in fact, isolates that varied in serotype and antibiograms showed identical restriction endonuclease profiles, whereas two indistinguishable isolates cultured from individual patients were easily and reproducibly differentiated by molecular analysis.
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PMID:Molecular study on nosocomial Pseudomonas aeruginosa strains. 251 20

The 163-kilobase-pair (kb) plasmid pMOL28, which determines inducible resistance to nickel, cobalt, chromate, and mercury salts in its native host Alcaligenes eutrophus CH34, was transferred to a derivative of A. eutrophus H16 and subjected to cloning procedures. After Tn5 transposon mutagenesis, restriction endonuclease analysis, and DNA-DNA hybridization, two DNA fragments, a 9.5-kb KpnI fragment and a 13.5-kb HindIII fragment (HKI), were isolated. HKI contained EK1, the KpnI fragment, as a subfragment flanked on both sides by short regions. Both fragments were ligated into the suicide vector pSUP202, the broad-host-range vector pVK101, and pUC19. Both fragments restored a nickel-sensitive Tn5 mutant to full nickel and cobalt resistance. The hybrid plasmid pVK101::HKI expressed full nickel resistance in all nickel-sensitive derivatives, either pMOL28-deficient or -defective, of the native host CH34. The hybrid plasmid pVK101::HKI also conferred nickel and cobalt resistance to A. eutrophus strains H16 and JMP222, Alcaligenes hydrogenophilus, Pseudomonas putida, and Pseudomonas oleovorans, but to a lower level of resistance. In all transconjugants the metal resistances coded by pVK101::HKI were expressed constitutively rather than inducibly. The hybrid plasmid metal resistance was not expressed in Escherichia coli. DNA sequences responsible for nickel resistance in newly isolated strains showed homology to the cloned pMOL28-encoded nickel and cobalt resistance determinant.
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PMID:Cloning of pMOL28-encoded nickel resistance genes and expression of the genes in Alcaligenes eutrophus and Pseudomonas spp. 254 12

Strains of Pseudomonas aeruginosa from patients with cystic fibrosis (CF) are unusual. The majority have a rough lipopolysaccharide (LPS) which renders them nontypeable by conventional typing systems based on a serological reaction with the O polysaccharide of smooth LPS. We developed a new typing scheme using a pilin gene probe as a marker for hybridization with endonuclease-digested genomic DNA from P. aeruginosa. Twenty-one different restriction fragment length polymorphism (RFLP) types were found among 249 isolates. RFLP type 7 was recovered only from patients with thermal burns (9 of 14 isolates) in both Vancouver, British Columbia, and Edmonton, Alberta, Canada. None of the other RFLP types showed a clear predilection for disease state or environmental niche. Multiple morphologically different isolates from individual patients with CF were studied; each isolate in 33 of 40 sputum samples had an identical RFLP type, despite considerable LPS serotype heterogeneity. Sequential isolates from 23 patients were studied; in 10 isolates there was a clear change in both the RFLP and the LPS serotype. We conclude that patients with CF usually harbor a single P. aeruginosa RFLP type in their sputa, but that one strain can replace another as the predominant colonizing type.
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PMID:Use of a pilin gene probe to study molecular epidemiology of Pseudomonas aeruginosa. 257 4

A bacterial strain, Pseudomonas sp. strain NK87, that can use 6-aminohexanoate-cyclic dimer as the sole source of carbon and nitrogen was newly isolated from wastewater of a factory which produces nylon-6. Two responsible enzymes, 6-aminohexanoate-cyclic-dimer hydrolase (P-EI) and 6-aminohexanoate-dimer hydrolase (P-EII), were found in the NK87 strain, as is the case with Flavobacterium sp. strain KI72, another 6-aminohexanoate-cyclic-dimer-metabolizing bacterium (H. Okada, S. Negoro, H. Kimura, and S. Nakamura, Nature [London] 306:203-206, 1983). The P-EI enzyme is immunologically identical to the 6-aminohexanoate-cyclic-dimer hydrolase of KI72 (F-EI). However, antiserum against the 6-aminohexanoate-dimer hydrolase purified from KI72 (F-EII) did not react with cell extracts of NK87, indicating that the F-EII and P-EII enzymes are immunologically different. Restriction endonuclease analyses show that the NK87 strain harbors at least six plasmids ranging in size from 20 to 80 kilobase pairs (kbp). The P-EI and P-EII genes were cloned in Escherichia coli. Both the P-EI and F-EI probes strongly hybridized with a 23-kbp plasmid in Southern hybridization analyses. The P-EII probe hybridized specifically with an 80-kbp plasmid, but the F-EII probe hybridized with none of the plasmids harbored in NK87. These results indicate that the P-EI gene and P-EII gene are encoded on the 23-kbp and 80-kbp plasmids, respectively.
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PMID:Plasmid dependence of Pseudomonas sp. strain NK87 enzymes that degrade 6-aminohexanoate-cyclic dimer. 272 45

Two Haemophilus influenzae Rd genes each complemented the pleiotropic defects of the recA-like mutation rec-1. One gene, fec, was isolated on a 3.6-kilobase-pair EcoRI restriction fragment by complementation of the Fec- phenotype of bacteriophage lambda. The other gene, rec, was identified on a 3.1-kilobase-pair EcoRI fragment by Southern hybridization by using recA-like gene probes from Erwinia carotovora and Pseudomonas aeruginosa PAO. In a rec-1 strain of H. influenzae, the cloned genes restored resistance to UV irradiation, transformation by chromosomal DNA, and spontaneous release of HP1 prophage to wild-type levels. The fec and rec genes were located on the cloned segments by insertion and deletion mutagenesis and subcloning. The restriction endonuclease cleavage maps of the two DNAs were similar but not identical. Southern hybridization demonstrated that the two EcoRI restriction fragments contained homologous DNA sequences, but a fec gene-specific probe was prepared. Each gene encoded a 38,000-dalton polypeptide.
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PMID:Two Haemophilus influenzae Rd genes that complement the recA-like mutation rec-1. 278 4


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