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:2.7.7.7 (DNA polymerase)
17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The opportunistic pathogen Pseudomonas aeruginosa produces type 4 fimbriae which promote adhesion to epithelial cells and are associated with a form of surface translocation called twitching motility. We have used transposon mutagenesis to identify loci required for fimbrial assembly or function by screening for mutants that lack the spreading colony morphology characteristic of twitching motility. A subset of these mutants is resistant to fimbria-specific phage. One of these mutants (R270) was found to contain a transposon insertion in a new gene, termed pilZ, which is located on chromosomal SpeI fragment I at about 40 min on the P. aeruginosa map, a position remote from other loci involved in fimbrial biogenesis. pilZ appears to be linked to and possibly forms an operon with a gene, holB*, which is homologous to the gene encoding the delta' subunit of Escherichia coli DNA polymerase III. The product of the pilZ gene is a protein of 118 amino acids (predicted molecular weight, 12,895) which probably has a cytoplasmic location. PilZ appears to be a new class of protein which has not hitherto been represented in the sequence databases, and its function is unknown. Complementation studies indicate that pilZ is able to restore the expression of fimbriae on the surface of P. aeruginosa, as well as twitching motility and sensitivity to fimbria-specific phage when provided in trans to the R270 mutant.
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PMID:Identification of a novel gene, pilZ, essential for type 4 fimbrial biogenesis in Pseudomonas aeruginosa. 855 Apr 41

Plasmids found in six strains of Thiobacillus ferrooxidans were mapped and compared in an effort to detect the origin of replication. Four strains yielded an identical 9.8-kb plasmid, pTFI91. Restriction mapping and Southern blot hybridization analysis were used to confirm this finding. Dissimilar plasmids found in two other strains contained a conserved 2.2-kb SacI region common to pTFI91. DNA sequence analysis of this region showed structural features common to bacterial plasmid replicons. A comparison of the pTFI91 origin with those of T. ferrooxidans pTF-FC2 and other broad host range vectors did not show significant homologous DNA sequences. To verify the replication function, a chloramphenicol acetyl transferase marker gene was ligated at the unique sites of pTFI91, and the plasmid was transformed into Escherichia coli DH5 alpha cells but no transformants were identified. To test the replication of pTFI91 independent of DNA polymerase I in E. coli, different restriction fragments of pTFI91 were cloned into pHSG398 (Cmr, ColEI origin) and transformed into the polA1 mutant SF800, but chloramphenicol-resistant transformants were not detected. Electrotransformation of T. ferrooxidans TFI-70 and Pseudomonas putida ATCC 19151 also failed to yield transformants. The results suggested that the pTFI91 plasmid replicon does not function either in E. coli or in P. putida. Since pTFI91 contains the same origin of replication as other plasmids in several other T. ferrooxidans strains, this replicon may be commonly distributed in T. ferrooxidans.
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PMID:Characterization of the pTFI91-family replicon of Thiobacillus ferrooxidans plasmids. 859 Apr 13

Bacteriophage phiKZ is a giant virus that efficiently infects Pseudomonas aeruginosa strains pathogenic to human and, therefore, it is attractive for phage therapy. We present here the complete phiKZ genome sequence and a preliminary analysis of its genome structure. The 280,334 bp genome is a linear, circularly permutated and terminally redundant, A+T-rich double-stranded DNA molecule. The phiKZ DNA has no detectable sequence homology to other viruses and microorganisms, and it does not contain NotI, PstI, SacI, SmaI, XhoI, and XmaIII endonuclease restriction sites. The genome has 306 open reading frames (ORFs) varying in size from 50 to 2237 amino acid residues. According to the orientation of transcription, ORFs are apparently organized into clusters and most have a clockwise direction. The phiKZ genome also encodes six tRNAs specific for Met (AUG), Asn (AAC), Asp (GAC), Leu (TTA), Thr (ACA), and Pro (CCA). A putative promoter sequence containing a TATATTAC block was identified. Most potential stem-loop transcription terminators contain the tetranucleotide UUCG loops. Some genes may be assigned as phage-encoded RNA polymerase subunits. Only 59 phiKZ gene products exhibit similarity to proteins of known function from a diversity of organisms. Most of these conserved gene products, such as dihydrofolate reductase, ribonucleoside diphosphate reductase, thymidylate synthase, thymidylate kinase, and deoxycytidine triphosphate deaminase are involved in nucleotide metabolism. However, no virus-encoded DNA polymerase, DNA replication-associated proteins, or single-stranded DNA-binding protein were found based on amino acid homology, and they may therefore be strongly divergent from known homologous proteins. Fifteen phiKZ gene products show homology to proteins of pathogenic organisms, including Mycobacterium tuberculosis, Haemophilus influenzae, Listeria sp., Rickettsia prowazakeri, and Vibrio cholerae that must be considered before using this phage as a therapeutic agent. The phiKZ coat contains at least 40 polypeptides, and several proteins are cleaved during virus assembly in a way similar to phage T4. Eleven phiKZ-encoded polypeptides are related to proteins of other bacteriphages that infect a variety of hosts. Among these are four gene products that contain a putative intron-encoded endonuclease harboring the H-N-H motif common to many double-stranded DNA phages. These observations provide evidence that phages infecting diverse hosts have had access to a common genetic pool. However, limited homology on the DNA and protein levels indicates that bacteriophage phiKZ represents an evolutionary distinctive branch of the Myoviridae family.
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PMID:The genome of bacteriophage phiKZ of Pseudomonas aeruginosa. 1191 76

Tap water is one of the causative factors of hospital infections. We examined the disinfective potential of electrolysis and mechanism of disinfection, and clarified the disinfective effect of electrolysis on tap water contaminated with bacteria, and discussed its clinical applications. Tap waters artificially contaminated with Pseudomonas aeruginosa, Escherichia coli, Legionella pneumophila, and Staphylococcus aureus could be sterilized by electrolysis at 20-30 mA for 5 min. A high-density suspension (10(6) CFU/ml) of a spore forming bacterium, Bacillus subtilis was not completely sterilized by electrolysis at 50 mA up to 30 min, but a low-density suspension (10(5) CFU/ml) was totally sterilized by electrolysis at 50 mA for 5 min. Electrolyzed P. aeruginosa changed morphologically, that is, there was bleb formation on the cell wall and irregular aggregation of cytoplasmic small granules. Moreover, cytoplasmic enzyme, nitrate reductase, was inactivated by the electrolysis. On the other hand, genomic DNA of the electrolyzed bacteria was not degenerated, therefore, their DNA polymerase activity was not completely inactivated. Consequently, the major agent in electrolysis for bactericidal action was considered to be free chlorine, and the possible bactericidal mechanism was by destruction of bacterial membranes, followed by the aggregation of peripheral cytoplasmic proteins. Electrolysis of tap water for both disinfecting contaminating bacteria and increasing the disinfectant capacity was considered effective with some limitations, particularly against high-density contamination by spore-forming bacteria. In clinical settings, electrolysis of tap water is considered effective to disinfect water for hand washing in operation theatres, and bathing water for immunocompromised hosts.
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PMID:Evaluation of disinfective potential of reactivated free chlorine in pooled tap water by electrolysis. 1506 56

In this work we studied involvement of DNA polymerase IV (Pol IV) (encoded by the dinB gene) in stationary-phase mutagenesis in Pseudomonas putida. For this purpose we constructed a novel set of assay systems that allowed detection of different types of mutations (e.g., 1-bp deletions and different base substitutions) separately. A significant effect of Pol IV became apparent when the frequency of accumulation of 1-bp deletion mutations was compared in the P. putida wild-type strain and its Pol IV-defective dinB knockout derivative. Pol IV-dependent mutagenesis caused a remarkable increase (approximately 10-fold) in the frequency of accumulation of 1-bp deletion mutations on selective plates in wild-type P. putida populations starved for more than 1 week. No effect of Pol IV on the frequency of accumulation of base substitution mutations in starving P. putida cells was observed. The occurrence of 1-bp deletions in P. putida cells did not require a functional RecA protein. RecA independence of Pol IV-associated mutagenesis was also supported by data showing that transcription from the promoter of the P. putida dinB gene was not significantly influenced by the DNA damage-inducing agent mitomycin C. Therefore, we hypothesize that mechanisms different from the classical RecA-dependent SOS response could elevate Pol IV-dependent mutagenesis in starving P. putida cells.
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PMID:Involvement of error-prone DNA polymerase IV in stationary-phase mutagenesis in Pseudomonas putida. 1509 May 15

The SOS response comprises a set of cellular functions aimed at preserving bacterial cell viability in front of DNA injuries. The SOS network, negatively regulated by the LexA protein, is found in many bacterial species that have not suffered major reductions in their gene contents, but presents distinctly divergent LexA-binding sites across the Bacteria domain. In this article, we report the identification and characterization of an imported multiple gene cassette in the Gamma Proteobacterium Pseudomonas putida that encodes a LexA protein, an inhibitor of cell division (SulA), an error-prone polymerase (DinP) and the alpha subunit of DNA polymerase III (DnaE). We also demonstrate that these genes constitute a DNA damage-inducible operon that is regulated by its own encoded LexA protein, and we establish that the latter is a direct derivative of the Gram-positive LexA protein. In addition, in silico analyses reveal that this multiple gene cassette is also present in many Proteobacteria families, and that both its gene content and LexA-binding sequence have evolved over time, ultimately giving rise to the lexA lineage of extant Gamma Proteobacteria.
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PMID:Widespread distribution of a lexA-regulated DNA damage-inducible multiple gene cassette in the Proteobacteria phylum. 1545 17

DNA polymerase III holoenzyme is responsible for chromosomal replication in bacteria. The components and functions of Escherichia coli DNA polymerase III holoenzyme have been studied extensively. Here, we report the reconstitution of replicase activity by essential components of DNA polymerase holoenzyme from the pathogen Pseudomonas aeruginosa. We have expressed and purified the processivity factor (beta), single-stranded DNA-binding protein, a complex containing the polymerase (alpha) and exonuclease (epsilon) subunits, and the essential components of the DnaX complex (tau(3)deltadelta'). Efficient primer elongation requires the presence of alphaepsilon, beta, and tau(3)deltadelta'. Pseudomonas aeruginosa alphaepsilon can substitute completely for E. coli polymerase III in E. coli holoenzyme reconstitution assays. Pseudomonas beta and tau(3)deltadelta' exhibit a 10-fold lower activity relative to their E. coli counterparts in E. coli holoenzyme reconstitution assays. Although the Pseudomonas counterpart to the E. coli psi subunit was not apparent in sequence similarity searches, addition of purified E. coli chi and psi (components of the DnaX complex) increases the apparent specific activity of the Pseudomonas tau(3)deltadelta' complex approximately 10-fold and enables the reconstituted enzyme to function better under physiological salt conditions.
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PMID:Reconstitution of a minimal DNA replicase from Pseudomonas aeruginosa and stimulation by non-cognate auxiliary factors. 1561 Oct 49

Plasmids in conjunction with other mobile elements such as transposons are major players in the genetic adaptation of bacteria in response to changes in environment. Here we show that a large catabolic TOL plasmid, pWW0, from Pseudomonas putida carries genes (rulAB genes) encoding an error-prone DNA polymerase Pol V homologue which increase the survival of bacteria under conditions of accumulation of DNA damage. A study of population dynamics in stationary phase revealed that the presence of pWW0-derived rulAB genes in the bacterial genome allows the expression of a strong growth advantage in stationary phase (GASP) phenotype of P. putida. When rulAB-carrying cells from an 8-day-old culture were mixed with Pol V-negative cells from a 1-day-old culture, cells derived from the aged culture out-competed cells from the nonaged culture and overtook the whole culture. At the same time, bacteria from an aged culture lacking the rulAB genes were only partially able to out-compete cells from a fresh overnight culture of the parental P. putida strain. Thus, in addition to conferring resistance to DNA damage, the plasmid-encoded Pol V genes significantly increase the evolutionary fitness of bacteria during prolonged nutritional starvation of a P. putida population. The results of our study indicate that RecA is involved in the control of expression of the pWW0-encoded Pol V.
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PMID:A DNA polymerase V homologue encoded by TOL plasmid pWW0 confers evolutionary fitness on Pseudomonas putida under conditions of environmental stress. 1603 Feb 14

We previously reconstituted a minimal DNA replicase from Pseudomonas aeruginosa consisting of alpha and epsilon (polymerase and editing nuclease), beta (processivity factor), and the essential tau, delta, and delta' components of the clamp loader complex (Jarvis, T., Beaudry, A., Bullard, J., Janjic, N., and McHenry, C. (2005) J. Biol. Chem. 280, 7890-7900). In Escherichia coli DNA polymerase III holoenzyme, chi and Psi are tightly associated clamp loader accessory subunits. The addition of E. coli chiPsi to the minimal P. aeruginosa replicase stimulated its activity, suggesting the existence of chi and Psi counterparts in P. aeruginosa. The P. aeruginosa chi subunit was recognizable from sequence similarity, but Psi was not. Here we report purification of an endogenous replication complex from P. aeruginosa. Identification of the components led to the discovery of the cryptic Psi subunit, encoded by holD. P. aeruginosa chi and Psi were co-expressed and purified as a 1:1 complex. P. aeruginosa chiPsi increased the specific activity of tau(3)deltadelta' 25-fold and enabled the holoenzyme to function under physiological salt conditions. A synergistic effect between chiPsi and single-stranded DNA binding protein was observed. Sequence similarity to P. aeruginosa Psi allowed us to identify Psi subunits from several other Pseudomonads and to predict probable translational start sites for this protein family. This represents the first identification of a highly divergent branch of the Psi family and confirms the existence of Psi in several organisms in which Psi was not identifiable based on sequence similarity alone.
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PMID:Discovery and characterization of the cryptic psi subunit of the pseudomonad DNA replicase. 1621 Mar 15

Isolated of multidrug resistance Pseudomonas aeruginosa (MDRP) that the receptivity pattern of the antimicrobial suscepti respectively resembled isolated from clinical specimens (sputum) in two patients of each internal medicine ward in Kitasato University East Hospital for two days from September 18 and 20, 2004. Both of bacteria were formed small colonies of a smooth-type on dollargalluskey improvement-type BTB agar plates, and the judgment of ClassB (metallo)-beta-lactamase by biochemical properties and disk diffusion method sodium mercaoto-acetic acid (SMA) was mutually corresponding. Moreover, it was same serotype C according to the serotype, and it was confirmed that it was the same bacterial strain from the molecular epidemiology analysis by Random amplified polymorphic DNA polymerase chain reaction (Random amplified polymorphic DNA polymerase chain reaction: RAPD). From the investigation of clinical backgrounds of two patients who isolated bacterial strains, September 18, 2004. 10 : 20 a.m., and 10 : 40 a.m., other chances that can become with contact infection in this hospital, except conducted X-Ray or roentgenograph of the chest and abdomen of Portable X-ray device continuously done by one radiation technician was not seen. Because it had turned out that a radiation technician who had taken charge had been neglecting the hand washing at the time of each X-Ray or roentgenograph, it was guessed the case with nosocomial infection by contact infection occurred via specific radiation technician.
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PMID:[Nosocomial infection by multidrug-resistant Pseudomonas Aeruginosa (MDRP) presumably spread a radiation technician]. 1662 93


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