scholarly journals Regulation and Characterization of the dadRAX Locus for D-Amino Acid Catabolism in Pseudomonas aeruginosa PAO1

2011 ◽  
Vol 193 (9) ◽  
pp. 2107-2115 ◽  
Author(s):  
W. He ◽  
C. Li ◽  
C.-D. Lu
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Amino Acid Catabolism ◽  
Pseudomonas Aeruginosa Pao1

scholarly journals Purification and Characterization of Pseudomonas aeruginosa PAO1 Asparaginase

2015 ◽  
Vol 28 ◽  
pp. 72-77 ◽  
Author(s):  
Takeshi Kuwabara ◽  
Asep A. Prihanto ◽  
Mamoru Wakayama ◽  
Kazuyoshi Takagi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Purification And Characterization ◽  
Pseudomonas Aeruginosa Pao1

scholarly journals Identification and Characterization of the Chemotactic Transducer in Pseudomonas aeruginosa PAO1 for Positive Chemotaxis to Trichloroethylene

2006 ◽  
Vol 188 (18) ◽  
pp. 6700-6702 ◽  
Author(s):  
Hye-Eun Kim ◽  
Maiko Shitashiro ◽  
Akio Kuroda ◽  
Noboru Takiguchi ◽  
Hisao Ohtake ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Triple Mutant ◽  
Pseudomonas Aeruginosa Pao1 ◽  
Chemotaxis Proteins ◽  
Identification And Characterization

ABSTRACT Pseudomonas aeruginosa PAO1 is repelled by trichloroethylene (TCE), and the methyl-accepting chemotaxis proteins PctA, PctB, and PctC serve as the major chemoreceptors for negative chemotaxis to TCE. In this study, we found that the pctABC triple mutant of P. aeruginosa PAO1 was attracted by TCE. Chemotaxis assays of a set of mutants containing deletions in 26 potential mcp genes revealed that mcpA (PA0180) is the chemoreceptor for positive chemotaxis to TCE. McpA also detects tetrachloroethylene and dichloroethylene isomers as attractants.

scholarly journals Functional Characterization of a Serine/Threonine Protein Kinase of Pseudomonas aeruginosa

1999 ◽  
Vol 67 (10) ◽  
pp. 5386-5394 ◽  
Author(s):  
S. Timothy Motley ◽  
Stephen Lory
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Protein Kinase ◽  
Protein Kinases ◽  
Catalytic Domain ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Single Amino Acid ◽  
Migration Behavior

ABSTRACT Protein kinases play a key role in signal transduction pathways in both eukaryotic and prokaryotic cells. Using in vivo expression technology, we have identified several promoters in Pseudomonas aeruginosa which are preferentially activated during infection of neutropenic mice. One of these promoters directs the transcription of a gene encoding a putative protein kinase similar to the enzymes found in eukaryotic cells. The full characterization of this protein, termed PpkA, is presented in this communication. The ppkA gene encodes a 1,032-amino-acid polypeptide with an N-terminal catalytic domain showing all of the conserved residues of protein kinases with the substrate phosphorylation specificities for serine and threonine residues. The catalytic domain is linked to the rest of the protein by a short proline-rich segment. The enzymes showed anomalous migration behavior when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which could be attributed to autophosphorylation activity. The full-length enzyme was expressed as an oligohistidine fusion protein and was shown to phosphorylate several artificial protein substrates. Both autophosphorylation and phosphorylation of added substrates were strongly reduced by a single-amino-acid substitution in the catalytic domain of PpkA. Although PpkA appears to be differentially phosphorylated by autocatalysis, the levels of phosphorylation have minimal effect on its overall enzymatic activity. Our results, therefore, indicate the operation of a novel protein phosphorylation mechanism during transduction of signals in P. aeruginosa, and this pathway may be important in regulating the expression of virulence factors by this pathogen during certain phases of infection.

scholarly journals Functional and Structural Characterization of OXA-935, a Novel OXA-10-family β-lactamase from Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Nathan B Pincus ◽  
Monica Rosas-Lemus ◽  
Samuel WM Gatesy ◽  
Ludmilla A. Shuvalova ◽  
Joseph Brunzelle ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Clonal Complex ◽  
Genomic Analysis ◽  
Catalytic Efficiency ◽  
Multidrug Resistant ◽  
Extended Spectrum ◽  
The Impact ◽  
Lactamase Inhibitor

Resistance to antipseudomonal penicillins and cephalosporins is often driven by the overproduction of the intrinsic β-lactamase AmpC. However, OXA-10-family β-lactamases are a rich source of resistance in Pseudomonas aeruginosa. OXA β-lactamases have a propensity for mutation leading to extended spectrum cephalosporinase and carbapenemase activity. In this study, we identified isolates from a subclade of the multidrug-resistant (MDR) high risk clonal complex CC446 with resistance to ceftazidime. Genomic analysis revealed that these isolates harbored a plasmid containing a novel allele of blaOXA-10, named blaOXA-935, which was predicted to produce an OXA-10 variant with two amino acid substitutions: an aspartic acid instead of glycine at position 157 and a serine instead of phenylalanine at position 153. The G157D mutation, present in OXA-14, is associated with resistance to ceftazidime. Deletion of blaOXA-935 restored sensitivity to ceftazidime and susceptibility profiling of P. aeruginosa laboratory strains expressing blaOXA-935 revealed that OXA-935 conferred ceftazidime resistance. To better understand the impact of the variant amino acids, we determined the crystal structures of OXA-14 and OXA-935. In contrast, both monomers of OXA-935 were decarbamylated at K70, and the F153S mutation conferred increased flexibility to the omega (Ω) loop. Compared to OXA-14, the catalytic efficiency of OXA-935 for nitrocefin was significantly reduced. Amino acid changes that confer extended spectrum cephalosporinase activity to OXA-10-family β-lactamases are concerning given rising reliance on novel β-lactam/β-lactamase inhibitor combinations such as ceftolozane-tazobactam and ceftazidime-avibactam to treat MDR P. aeruginosa infections.

scholarly journals Molecular Characterization of OXA-20, a Novel Class D β-Lactamase, and Its Integron from Pseudomonas aeruginosa

1998 ◽  
Vol 42 (8) ◽  
pp. 2074-2083 ◽  
Author(s):  
Thierry Naas ◽  
Wladimir Sougakoff ◽  
Anne Casetta ◽  
Patrice Nordmann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Clavulanic Acid ◽  
Antibiotic Resistance Gene ◽  
Amino Acid Identity ◽  
Acid Identity ◽  
Class D ◽  
Acid Protein ◽  
Amino Acid Protein

ABSTRACT The Pseudomonas aeruginosa Mus clinical isolate produces OXA-18, a pI 5.5 class D extended-spectrum β-lactamase totally inhibited by clavulanic acid (L. N. Philippon, T. Naas, A.-T. Bouthors, V. Barakett, and P. Nordmann, Antimicrob. Agents Chemother. 41:2188–2195, 1997). A second β-lactamase was cloned, and the recombinant Escherichia coli clone pPL10 expressed a pI 7.4 β-lactamase which conferred high levels of amoxicillin and ticarcillin resistance and which was partially inhibited by clavulanic acid. The 2.5-kb insert from pPL10 was sequenced, and a 266-amino-acid protein (OXA-20) was deduced; this protein has low amino acid identity with most of the class D β-lactamases except OXA-2, OXA-15, and OXA-3 (75% amino acid identity with each). OXA-20 is a restricted-spectrum oxacillinase and is unusually inhibited by clavulanic acid. OXA-20 is a peculiar β-lactamase because its translation initiates with a TTG (leucine) codon, which is rarely used as a translational origin in bacteria. Exploration of the genetic environment of oxa20revealed the presence of the following integron features: (i) a second antibiotic resistance gene, aacA4; (ii) anintI1 gene; and (iii) two 59-base elements, each associated with either oxa20 or aacA4. This integron is peculiar because it lacks the 3′ conserved region, and therefore is not a sul1-associated integron like most of them, and because its 3′ end is located within tnpR, a gene involved in the transposition of Tn5393, a gram-negative transposon.P. aeruginosa Mus produces two novel and unrelated oxacillinases, OXA-18 and OXA-20, both of which are inhibited by clavulanic acid.

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