A bacterial periplasmic receptor homologue with catalytic activity: cyclohexadienyl dehydratase of Pseudomonas aeruginosa is homologous to receptors specific for polar amino acids

1993 ◽  
Vol 144 (3) ◽  
pp. 165-169 ◽  
Author(s):  
R. Tam ◽  
M.H. Saier
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Catalytic Activity

scholarly journals The amino acid sequence of cytochromes c-551 from three species of Pseudomonas

1973 ◽  
Vol 131 (3) ◽  
pp. 485-498 ◽  
Author(s):  
R. P. Ambler ◽  
Margaret Wynn
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Cytochrome C ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Mitochondrial Cytochrome ◽  
Cytochromes C ◽  
Lending Library ◽  
Single Peptide

The amino acid sequences of the cytochromes c-551 from three species of Pseudomonas have been determined. Each resembles the protein from Pseudomonas strain P6009 (now known to be Pseudomonas aeruginosa, not Pseudomonas fluorescens) in containing 82 amino acids in a single peptide chain, with a haem group covalently attached to cysteine residues 12 and 15. In all four sequences 43 residues are identical. Although by bacteriological criteria the organisms are closely related, the differences between pairs of sequences range from 22% to 39%. These values should be compared with the differences in the sequence of mitochondrial cytochrome c between mammals and amphibians (about 18%) or between mammals and insects (about 33%). Detailed evidence for the amino acid sequences of the proteins has been deposited as Supplementary Publication SUP 50015 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 5.

scholarly journals Auto‐ADP‐ribosylation inhibits the catalytic activity of ExoS, a type‐III effector of Pseudomonas aeruginosa

2006 ◽  
Vol 20 (4) ◽  
Author(s):  
Linda Ann Stevens ◽  
Sunhee Park ◽  
Joseph Barbieri ◽  
Rita Bortell ◽  
Joel Moss
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Catalytic Activity ◽  
Type Iii Effector ◽  
Adp Ribosylation ◽  
Type Iii

scholarly journals Amino Acid-Mediated Induction of the Basic Amino Acid-Specific Outer Membrane Porin OprD from Pseudomonas aeruginosa

1999 ◽  
Vol 181 (17) ◽  
pp. 5426-5432 ◽  
Author(s):  
Martina M. Ochs ◽  
Chung-Dar Lu ◽  
Robert E. W. Hancock ◽  
Ahmed T. Abdelal
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Regulatory Protein ◽  
Basic Amino Acid ◽  
Sole Source ◽  
Activation Mechanism ◽  
Beta Lactam ◽  
Mobility Shift ◽  
Carbon And Nitrogen

ABSTRACT Pseudomonas aeruginosa can utilize arginine and other amino acids as both carbon and nitrogen sources. Earlier studies have shown that the specific porin OprD facilitates the diffusion of basic amino acids as well as the structurally analogous beta-lactam antibiotic imipenem. The studies reported here showed that the expression of OprD was strongly induced when arginine, histidine, glutamate, or alanine served as the sole source of carbon. The addition of succinate exerted a negative effect on induction ofoprD, likely due to catabolite repression. The arginine-mediated induction was dependent on the regulatory protein ArgR, and binding of purified ArgR to its operator upstream of theoprD gene was demonstrated by gel mobility shift and DNase assays. The expression of OprD induced by glutamate as the carbon source, however, was independent of ArgR, indicating the presence of more than a single activation mechanism. In addition, it was observed that the levels of OprD responded strongly to glutamate and alanine as the sole sources of nitrogen. Thus, that the expression ofoprD is linked to both carbon and nitrogen metabolism ofPseudomonas aeruginosa.

scholarly journals Human xylosyltransferase I and N-terminal truncated forms: functional characterization of the core enzyme

2006 ◽  
Vol 394 (1) ◽  
pp. 163-171 ◽  
Author(s):  
Sandra Müller ◽  
Jennifer Disse ◽  
Manuela Schöttler ◽  
Sylvia Schön ◽  
Christian Prante ◽  
...  
Keyword(s):  
Amino Acids ◽  
Catalytic Activity ◽  
Binding Capacity ◽  
Functional Characterization ◽  
Terminal Region ◽  
Binding Motif ◽  
Heparin Binding ◽  
Loss Of Function ◽  
The Impact

Human XT-I (xylosyltransferase I; EC 2.4.2.26) initiates the biosynthesis of the glycosaminoglycan linkage region and is a diagnostic marker of an enhanced proteoglycan biosynthesis. In the present study, we have investigated mutant enzymes of human XT-I and assessed the impact of the N-terminal region on the enzymatic activity. Soluble mutant enzymes of human XT-I with deletions at the N-terminal domain were expressed in insect cells and analysed for catalytic activity. As many as 260 amino acids could be truncated at the N-terminal region of the enzyme without affecting its catalytic activity. However, truncation of 266, 272 and 273 amino acids resulted in a 70, 90 and >98% loss in catalytic activity. Interestingly, deletion of the single 12 amino acid motif G261KEAISALSRAK272 leads to a loss-of-function XT-I mutant. This is in agreement with our findings analysing the importance of the Cys residues where we have shown that C276A mutation resulted in a nearly inactive XT-I enzyme. Moreover, we investigated the location of the heparin-binding site of human XT-I using the truncated mutants. Heparin binding was observed to be slightly altered in mutants lacking 289 or 568 amino acids, but deletion of the potential heparin-binding motif P721KKVFKI727 did not lead to a loss of heparin binding capacity. The effect of heparin or UDP on the XT-I activity of all mutants was not significantly different from that of the wild-type. Our study demonstrates that over 80% of the nucleotide sequence of the XT-I-cDNA is necessary for expressing a recombinant enzyme with full catalytic activity.

STUDIES ON THE BIOSYNTHESIS OF PYOCYANINE

1962 ◽  
Vol 8 (1) ◽  
pp. 49-56 ◽  
Author(s):  
J. M. Ingram ◽  
A. C. Blackwood
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Oxalic Acid ◽  
Dicarboxylic Acid ◽  
Sodium Formate ◽  
Complete Medium ◽  
Tetracarboxylic Acid ◽  
Dipotassium Salt

The biosynthesis of pyocyanine, the blue phenazine pigment produced by Pseudomonas aeruginosa, was studied by the addition of radioactive substrates to a culture growing on a complete medium. The distribution of labelled carbon from radioactive substrates in the pyocyanine was examined by degrading the pigment to 1-hydroxyphenazine, quinoxaline dicarboxylic acid, quinoxaline, and pyrazine tetracarboxylic acid dipotassium salt, and thus 7 of the 13 carbons were assayed separately or in pairs.Glycerol-1,3-C14 is the principal donor of radioactivity to the pyocyanine carbon, but not all the carbon atoms tested were labeled. Alanine-U-C14 contributed carbon to pyocyanine also, but not to all carbons, and at a much lower level of efficiency than glycerol. However, with leucine-U-C14, all carbon atoms tested were labeled to a slight extent. These amino acids, when labeled specifically, and glutamate-U-C14, oxalic acid-C14, and sodium formate-C14 did not contribute significantly to pyocyanine carbon.The distribution of radioactivity from glycerol in the pyocyanine molecule suggests the pigment is formed from glycerol or a product closely related to it by the condensation of two carbon units or the condensation of four and two carbon units.

scholarly journals Exclusive Use of trans-Editing Domains Prevents Proline Mistranslation

2013 ◽  
Vol 288 (20) ◽  
pp. 14391-14399 ◽  
Author(s):  
Oscar Vargas-Rodriguez ◽  
Karin Musier-Forsyth
Keyword(s):  
Amino Acids ◽  
Catalytic Activity ◽  
Bioinformatics Analysis ◽  
Caulobacter Crescentus ◽  
Protein A ◽  
Elongation Factor ◽  
Single Domain ◽  
Elongation Factor Tu ◽  
Trna Synthetases ◽  
Aminoacyl Trna Synthetases

Aminoacyl-tRNA synthetases (ARSs) catalyze the attachment of specific amino acids to cognate tRNAs. Although the accuracy of this process is critical for overall translational fidelity, similar sizes of many amino acids provide a challenge to ARSs. For example, prolyl-tRNA synthetases (ProRSs) mischarge alanine and cysteine onto tRNAPro. Many bacterial ProRSs possess an alanine-specific proofreading domain (INS) but lack the capability to edit Cys-tRNAPro. Instead, Cys-tRNAPro is cleared by a single-domain homolog of INS, the trans-editing YbaK protein. A global bioinformatics analysis revealed that there are six types of “INS-like” proteins. In addition to INS and YbaK, four additional single-domain homologs are widely distributed throughout bacteria: ProXp-ala (formerly named PrdX), ProXp-x (annotated as ProX), ProXp-y (annotated as YeaK), and ProXp-z (annotated as PA2301). The last three are domains of unknown function. Whereas many bacteria encode a ProRS containing an INS domain in addition to YbaK, many other combinations of INS-like proteins exist throughout the bacterial kingdom. Here, we focus on Caulobacter crescentus, which encodes a ProRS with a truncated INS domain that lacks catalytic activity, as well as YbaK and ProXp-ala. We show that C. crescentus ProRS can readily form Cys- and Ala-tRNAPro, and deacylation studies confirmed that these species are cleared by C. crescentus YbaK and ProXp-ala, respectively. Substrate specificity of C. crescentus ProXp-ala is determined, in part, by elements in the acceptor stem of tRNAPro and further ensured through collaboration with elongation factor Tu. These results highlight the diversity of approaches used to prevent proline mistranslation and reveal a novel triple-sieve mechanism of editing that relies exclusively on trans-editing factors.

scholarly journals SECRETION OF PLASMINOGEN ACTIVATOR BY STIMULATED MACROPHAGES

1974 ◽  
Vol 139 (4) ◽  
pp. 834-850 ◽  
Author(s):  
Jay C. Unkeless ◽  
Saimon Gordon ◽  
E. Reich
Keyword(s):  
Amino Acids ◽  
Catalytic Activity ◽  
Plasminogen Activator ◽  
Electrophoretic Mobility ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Plasminogen Activators ◽  
Peritoneal Macrophages ◽  
Chemical Labeling ◽  
Specific Catalytic Activity

Cultured thioglycollate-stimulated peritoneal macrophages synthesize, accumulate, and continuously release high levels of plasminogen activators for at least 4 days whereas cultures of unstimulated macrophages do not; the higher specific catalytic activity of released vs. cell-associated enzyme suggests that the plasminogen activators are actively secreted. The major macrophage plasminogen activator is a serine protease of mol wt 48,000, and thus resembles the comparable enzyme released by virally transformed fibroblasts. Macrophages release a second plasminogen activator of mol wt 28,000 that is also a serine enzyme. The secretion products released by stimulated and unstimulated macrophages have been compared by SDS-polyacrylamide gel electrophoresis after chemical labeling with 3H-DFP or biosynthetic labeling with 14C-amino acids. These procedures show that some proteins are formed in both cultures, whereas others are uniquely secreted by each type of macrophage. The serine enzymes released by the two kinds of macrophages differ in specificity and electrophoretic mobility.

Studies on the Catalytic Activity of Poly-α-amino Acids

1970 ◽  
Vol 67 (1) ◽  
pp. 103-111 ◽  
Author(s):  
HIROYUKI YAMAMOTO ◽  
JUNZO NOGUCHI
Keyword(s):  
Amino Acids ◽  
Catalytic Activity

scholarly journals Negative Regulation of the Pseudomonas aeruginosa Outer Membrane Porin OprD Selective for Imipenem and Basic Amino Acids

1999 ◽  
Vol 43 (5) ◽  
pp. 1085-1090 ◽  
Author(s):  
Martina M. Ochs ◽  
Matthew P. McCusker ◽  
Manjeet Bains ◽  
Robert E. W. Hancock
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Clinical Effectiveness ◽  
Multiple Antibiotic Resistance ◽  
Outer Membranes ◽  
Basic Amino Acids ◽  
Outer Membrane Porin ◽  
Strong Homology ◽  
Imipenem Resistance

ABSTRACT Pseudomonas aeruginosa OprD is a specific porin which facilitates the uptake of basic amino acids and imipenem, a carbapenem antibiotic. Resistance to imipenem due to the loss of OprD is an important mechanism for the loss of clinical effectiveness. To investigate the negative regulatory mechanisms influencingoprD expression, a gene upstream of the coregulatedmexEF-oprN efflux operon, designated mexT, was cloned. The predicted 304-amino-acid mature MexT protein showed strong homology to LysR-type regulators. When overexpressed it induced the expression of the mexEF-oprN efflux operon while decreasing the level of expression of OprD. The use of anoprD::xylE transcriptional fusion indicated that it acted by repressing the transcription ofoprD. Salicylate, a weak aromatic acid known to reduce porin expression and induce low levels of multiple antibiotic resistance in Escherichia coli, was able to induce imipenem resistance and reduce the expression of OprD but not multiple antibiotic resistance or OprN expression in P. aeruginosa. This was also demonstrated to occur at the level of transcription. Acetyl salicylate and benzoate, but not catechol, were also able to reduce the levels of OprD in the P. aeruginosa outer membranes. These OprD-suppressing compounds increased imipenem resistance even in a mexT-overexpressing andnfxC mutant backgrounds, suggesting that such resistance is independent of the MexT repressor and that oprD is influenced by more than a single mechanism of repression.

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