scholarly journals Free and membrane-bound forms of bacterial cytochrome c4

1988 ◽  
Vol 252 (2) ◽  
pp. 427-435 ◽  
Author(s):  
G W Pettigrew ◽  
K R Brown
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Azotobacter Vinelandii ◽  
Pseudomonas Stutzeri ◽  
Growth Conditions ◽  
Free Form ◽  
Aerobic Growth ◽  
Cytochromes C ◽  
Membrane Bound ◽  
Solubilized Form ◽  
Attached Form

Cytochrome c4 was isolated from cells of Pseudomonas aeruginosa, Pseudomonas stutzeri and Azotobacter vinelandii. The dihaem nature, Mr of approx. 20,000 and ferrohaem spectra in the region of the alpha- and beta-peaks define this family of cytochromes c. The behaviour of the holocytochromes in SDS was atypical, but removal of the haem groups resulted in a normal migration. In all three organisms most of the cytochrome c4 was tightly bound to the membrane, but some free cytochrome was detected. The membrane-attached cytochrome could be extracted with butanol, and this solubilized form was then indistinguishable in properties from the free form. Denitrifying rather than aerobic growth conditions hardly affected the total cytochrome c4 in the two pseudomonads, but there was slightly more free form and less membrane-attached form in denitrifying growth. The nature of the attachment of cytochrome c4 to the membrane is discussed and a model is proposed for the process of solubilization.

scholarly journals The role of cytochrome c4 in bacterial respiration. Cellular location and selective removal from membranes

1989 ◽  
Vol 262 (1) ◽  
pp. 233-240 ◽  
Author(s):  
D J B Hunter ◽  
K R Brown ◽  
G W Pettigrew
Keyword(s):  
Oxidase Activity ◽  
Sodium Iodide ◽  
Azotobacter Vinelandii ◽  
Pseudomonas Stutzeri ◽  
Selective Removal ◽  
Bacterial Respiration ◽  
Cellular Location ◽  
Diamine Oxidase Activity ◽  
Membrane Bound

The cellular location of cytochrome c4 in Pseudomonas stutzeri and Azotobacter vinelandii was investigated by the production of spheroplasts. Soluble cytochrome c4 was found to be located in the periplasm in both organisms. The remaining cytochrome c4 was membrane-bound. The orientation of this membrane-bound cytochrome c4 fraction was investigated by proteolysis of the cytochrome on intact spheroplasts. In P. stutzeri, 78% of the membrane-bound cytochrome c4 could be proteolysed, whilst 82% of the spheroplasts remained intact, suggesting that the membrane-bound cytochrome c4 is on the periplasmic face of the membrane in this organism. Cytochrome c4 was not susceptible to proteolysis on A. vinelandii spheroplasts, in spite of being digestible in the purified state. Cytochrome c5 was shown to have a similar cellular distribution to cytochrome c4. Selective removal of cytochrome c4 from membranes of P. stutzeri was accomplished by the use of sodium iodide and propan-2-ol, with the retention of most of the ascorbate-TMPD (NNN‘N’-tetramethylbenzene-1,4-diamine) oxidase activity associated with the membrane. Sodium iodide removed most of the cytochrome c4 from A. vinelandii membranes with retention of 62% of the ascorbate-TMPD oxidase activity. Cytochrome c4 could be returned to the washed membranes, but with no recovery of this enzyme activity. We conclude that cytochrome c4 is not involved in the ascorbate-TMPD oxidase activity associated with the membranes of these two organisms.

scholarly journals Arginine or Nitrate Enhances Antibiotic Susceptibility of Pseudomonas aeruginosa in Biofilms

2006 ◽  
Vol 50 (1) ◽  
pp. 382-384 ◽  
Author(s):  
Giorgia Borriello ◽  
Lee Richards ◽  
Garth D. Ehrlich ◽  
Philip S. Stewart
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Susceptibility ◽  
Viable Cell ◽  
Growth Conditions ◽  
Aerobic Growth ◽  
Cell Counts

ABSTRACT Arginine enhanced the killing of Pseudomonas aeruginosa by ciprofloxacin and tobramycin under anaerobic, but not aerobic, growth conditions. Arginine or nitrate also enhanced the killing by these antibiotics in mature biofilms, reducing viable cell counts by a factor of 10 to 100 beyond that achieved by antibiotics alone.

scholarly journals Synthesis of alternative membrane-bound redox carriers during aerobic growth of Escherichia coli in the presence of potassium cyanide

1975 ◽  
Vol 148 (2) ◽  
pp. 349-352 ◽  
Author(s):  
J R Ashcroft ◽  
B A Haddock
Keyword(s):  
Escherichia Coli ◽  
Electron Transport ◽  
Carbon Source ◽  
Potassium Cyanide ◽  
Growth Conditions ◽  
Aerobic Growth ◽  
E Coli ◽  
Low Concentrations ◽  
Electron Transport Chains ◽  
Membrane Bound

Aerobic growth of Escherichia coli with an oxidizable substrate as carbon source in the presence of low concentrations of KCN leads to the synthesis and integration into the membrane of menaquinone and cytochromes b558, a1 and d in addition to the redox carriers normally present under aerobic growth conditions, namely ubiquinone and cytochromes b562, b556 and o. The results are discussed with reference to other phenotypic and genotypic modifications to the electron-transport chains of E. coli.

scholarly journals Phosphorus stress induces the synthesis of novel glycolipids in Pseudomonas aeruginosa that confer protection against a last-resort antibiotic

2021 ◽  
Author(s):  
Rebekah A. Jones ◽  
Holly Shropshire ◽  
Caimeng Zhao ◽  
Andrew Murphy ◽  
Ian Lidbury ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Antibiotic Sensitivity ◽  
Polymyxin B ◽  
Growth Conditions ◽  
Membrane Lipid ◽  
Comparative Genomic ◽  
P Limitation ◽  
Lung Microbiome ◽  
Glycolipid Synthesis

AbstractPseudomonas aeruginosa is a nosocomial pathogen with a prevalence in immunocompromised individuals and is particularly abundant in the lung microbiome of cystic fibrosis patients. A clinically important adaptation for bacterial pathogens during infection is their ability to survive and proliferate under phosphorus-limited growth conditions. Here, we demonstrate that P. aeruginosa adapts to P-limitation by substituting membrane glycerophospholipids with sugar-containing glycolipids through a lipid renovation pathway involving a phospholipase and two glycosyltransferases. Combining bacterial genetics and multi-omics (proteomics, lipidomics and metatranscriptomic analyses), we show that the surrogate glycolipids monoglucosyldiacylglycerol and glucuronic acid-diacylglycerol are synthesised through the action of a new phospholipase (PA3219) and two glycosyltransferases (PA3218 and PA0842). Comparative genomic analyses revealed that this pathway is strictly conserved in all P. aeruginosa strains isolated from a range of clinical and environmental settings and actively expressed in the metatranscriptome of cystic fibrosis patients. Importantly, this phospholipid-to-glycolipid transition comes with significant ecophysiological consequence in terms of antibiotic sensitivity. Mutants defective in glycolipid synthesis survive poorly when challenged with polymyxin B, a last-resort antibiotic for treating multi-drug resistant P. aeruginosa. Thus, we demonstrate an intriguing link between adaptation to environmental stress (nutrient availability) and antibiotic resistance, mediated through membrane lipid renovation that is an important new facet in our understanding of the ecophysiology of this bacterium in the lung microbiome of cystic fibrosis patients.

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 Genetic determinants of Pseudomonas aeruginosa biofilm establishment

Microbiology ◽  
2010 ◽  
Vol 156 (2) ◽  
pp. 431-441 ◽  
Author(s):  
Mathias Müsken ◽  
Stefano Di Fiore ◽  
Andreas Dötsch ◽  
Rainer Fischer ◽  
Susanne Häussler
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Laser Scanning ◽  
Growth Conditions ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Repair System ◽  
Ph Homeostasis ◽  
Genetic Determinants ◽  
Complex Process ◽  
Genes Encoding

The establishment of bacterial biofilms on surfaces is a complex process that requires various factors for each consecutive developmental step. Here we report the screening of the comprehensive Harvard Pseudomonas aeruginosa PA14 mutant library for mutants exhibiting an altered biofilm phenotype. We analysed the capability of all mutants to form biofilms at the bottom of a 96-well plate by the use of an automated confocal laser-scanning microscope and found 394 and 285 genetic determinants of reduced and enhanced biofilm production, respectively. Overall, 67 % of the identified mutants were affected within genes encoding hypothetical proteins, indicating that novel developmental pathways are likely to be dissected in the future. Nevertheless, a common theme that emerged from the analysis of the genes with a predicted function is that the establishment of a biofilm requires regulatory components that are involved in survival under microaerophilic growth conditions, arginine metabolism, alkyl-quinolone signalling, pH homeostasis and the DNA repair system.

scholarly journals Glucose Signaling Pathway and Growth Conditions Regulate Gene Expression in Retrotransposon Ty2

2009 ◽  
Vol 64 (7-8) ◽  
pp. 526-532 ◽  
Author(s):  
Sezai Türkel ◽  
Özgür Bayram ◽  
Elif Arık
Keyword(s):  
Gene Expression ◽  
Growth Conditions ◽  
Glucose Sensors ◽  
Yeast Cells ◽  
Growth Stages ◽  
Regulate Gene Expression ◽  
Glucose Signaling ◽  
Yeast Cultures ◽  
Membrane Bound ◽  
High Level

Gene expression in the yeast retrotransposon Ty2 is regulated at transcriptional and translational levels. In this study, we have shown that the transcription of Ty2 is partially dependent on the membrane-bound glucose sensors Gpr1p and Mth1p in Saccharomyces cerevisiae. Transcription of Ty2 decreased approx. 3-fold in the gpr1, mth1 yeast mutant. Moreover, our results revealed that the transcription of Ty2 fluctuates during the growth stages of S. cerevisae. Both transcription and the frameshift rate of Ty2 rapidly dropped when the stationary stage yeast cells were inoculated into fresh medium. There was an instant activation of Ty2 transcription and a high level expression during the entire logarithmic stage of yeast growth. However, the transcription of Ty2 decreased 2-fold when the yeast cultures entered the stationary stage. The frameshift rate in Ty2 also varied depending on the growth conditions. The highest frameshift level was observed during the mid-logarithmic stage. It decreased up to 2-fold during the stationary stage. Furthermore, we have found that the frameshift rate of Ty2 diminished at least 5-fold in slowly growing yeasts. These results indicate that the transcription and the frameshift efficiency are coordinately regulated in the retrotransposon Ty2 depending on the growth conditions of S. cerevisiae.

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