Expression of Streptomyces genes encoding extracellular enzymes in Brevibacterium lactofermentum: secretion proceeds by removal of the same leader peptide as in Streptomyces lividans

1992 ◽  
Vol 38 (3) ◽  
Author(s):  
RosaF. Cadenas ◽  
Jos�A. Gil ◽  
JuanF. Martin
Keyword(s):  
Extracellular Enzymes ◽  
Streptomyces Lividans ◽  
Leader Peptide ◽  
Brevibacterium Lactofermentum ◽  
Genes Encoding

Mig1 is involved in mycelial formation and expression of the genes encoding extracellular enzymes in Saccharomycopsis fibuligera A11

2011 ◽  
Vol 48 (9) ◽  
pp. 904-913 ◽  
Author(s):  
Guang-Lei Liu ◽  
Dong-Sheng Wang ◽  
Ling-Fei Wang ◽  
Shou-Feng Zhao ◽  
Zhen-Ming Chi
Keyword(s):  
Extracellular Enzymes ◽  
Saccharomycopsis Fibuligera ◽  
Genes Encoding

scholarly journals Genomics Reveals the Metabolic Potential and Functions in the Redistribution of Dissolved Organic Matter in Marine Environments of the Genus Thalassotalea

2020 ◽  
Vol 8 (9) ◽  
pp. 1412
Author(s):  
Minji Kim ◽  
In-Tae Cha ◽  
Ki-Eun Lee ◽  
Eun-Young Lee ◽  
Soo-Je Park
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Extracellular Enzymes ◽  
Marine Invertebrates ◽  
Carbon Sources ◽  
Marine Environments ◽  
Metabolic Potential ◽  
Carbohydrate Utilization ◽  
Genes Encoding ◽  
Metagenomic Study

Members of the bacterial genus Thalassotalea have been isolated recently from various marine environments, including marine invertebrates. A metagenomic study of the Deepwater Horizon oil plume has identified genes involved in aromatic hydrocarbon degradation in the Thalassotalea genome, shedding light on its potential role in the degradation of crude oils. However, the genomic traits of the genus are not well-characterized, despite the ability of the species to degrade complex natural compounds, such as agar, gelatin, chitin, or starch. Here, we obtained a complete genome of a new member of the genus, designated PS06, isolated from marine sediments containing dead marine benthic macroalgae. Unexpectedly, strain PS06 was unable to grow using most carbohydrates as sole carbon sources, which is consistent with the finding of few ABC transporters in the PS06 genome. A comparative analysis of 12 Thalassotalea genomes provided insights into their metabolic potential (e.g., microaerobic respiration and carbohydrate utilization) and evolutionary stability [including a low abundance of clustered regularly interspaced short palindromic repeats (CRISPR) loci and prophages]. The diversity and frequency of genes encoding extracellular enzymes for carbohydrate metabolism in the 12 genomes suggest that members of Thalassotalea contribute to nutrient cycling by the redistribution of dissolved organic matter in marine environments. Our study improves our understanding of the ecological and genomic properties of the genus Thalassotalea.

scholarly journals Catabolism of l-rhamnose in A. nidulans proceeds via the non-phosphorylated pathway and is glucose repressed by a CreA-independent mechanism

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Andrew P. MacCabe ◽  
Elpinickie I. Ninou ◽  
Ester Pardo ◽  
Margarita Orejas
Keyword(s):  
Transcription Factor ◽  
Filamentous Fungus ◽  
Extracellular Enzymes ◽  
Regulatory Mechanisms ◽  
Bioactive Metabolites ◽  
Free Sugar ◽  
Knock Out ◽  
Independent Mechanism ◽  
Genes Encoding ◽  
Specific Uptake

Abstract l-rhamnose (6-deoxy-mannose) occurs in nature mainly as a component of certain plant structural polysaccharides and bioactive metabolites but has also been found in some microorganisms and animals. The release of l-rhamnose from these substrates is catalysed by extracellular enzymes including α-l-rhamnosidases, the production of which is induced in its presence. The free sugar enters cells via specific uptake systems where it can be metabolized. Of two l-rhamnose catabolic pathways currently known in microorganisms a non-phosphorylated pathway has been identified in fungi and some bacteria but little is known of the regulatory mechanisms governing it in fungi. In this study two genes (lraA and lraB) are predicted to be involved in the catabolism of l-rhamnose, along with lraC, in the filamentous fungus Aspergillus nidulans. Transcription of all three is co-regulated with that of the genes encoding α-l-rhamnosidases, i.e. induction mediated by the l-rhamnose-responsive transcription factor RhaR and repression of induction in the presence of glucose via a CreA-independent mechanism. The participation of lraA/AN4186 (encoding l-rhamnose dehydrogenase) in l-rhamnose catabolism was revealed by the phenotypes of knock-out mutants and their complemented strains. lraA deletion negatively affects both growth on l-rhamnose and the synthesis of α-l-rhamnosidases, indicating not only the indispensability of this pathway for l-rhamnose utilization but also that a metabolite derived from this sugar is the true physiological inducer.

scholarly journals Multiple Mutations Lead to MexXY-OprM-Dependent Aminoglycoside Resistance in Clinical Strains of Pseudomonas aeruginosa

2013 ◽  
Vol 58 (1) ◽  
pp. 221-228 ◽  
Author(s):  
Sophie Guénard ◽  
Cédric Muller ◽  
Laura Monlezun ◽  
Philippe Benas ◽  
Isabelle Broutin ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Multidrug Resistant ◽  
Single Amino Acid ◽  
Leader Peptide ◽  
Dimerization Domain ◽  
Aminoglycoside Resistance ◽  
Content Type ◽  
Clinical Strains ◽  
Genes Encoding

ABSTRACTConstitutive overproduction of the pump MexXY-OprM is recognized as a major cause of resistance to aminoglycosides, fluoroquinolones, and zwitterionic cephalosporins inPseudomonas aeruginosa. In this study, 57 clonally unrelated strains recovered from non-cystic fibrosis patients were analyzed to characterize the mutations resulting in upregulation of themexXYoperon. Forty-four (77.2%) of the strains, classified asagrZmutants were found to harbor mutations inactivating the local repressor gene (mexZ) of themexXYoperon (n= 33; 57.9%) or introducing amino acid substitutions in its product, MexZ (n= 11; 19.3%). These sequence variations, which mapped in the dimerization domain, the DNA binding domain, or the rest of the MexZ structure, mostly affected amino acid positions conserved in TetR-like regulators. The 13 remaining MexXY-OprM strains (22.8%) contained intactmexZgenes encoding wild-type MexZ proteins. Eight (14.0%) of these isolates, classified asagrW1mutants, overexpressed the gene PA5471, which codes for the MexZ antirepressor AmrZ, with 5 strains exhibiting growth defects at 37°C and 44°C, consistent with mutations impairing ribosome activity. Interestingly, oneagrW1mutant appeared to harbor a 7-bp deletion in the coding sequence of the leader peptide, PA5471.1, involved in ribosome-dependent, translational attenuation of PA5471 expression. Finally, DNA sequencing and complementation experiments revealed that 5 (8.8%) strains, classified asagrW2mutants, harbored single amino acid variations in the sensor histidine kinase of ParRS, a two-component system known to positively controlmexXYexpression. Collectively, these results demonstrate that clinical strains ofP. aeruginosaexploit different regulatory circuitries to mutationally overproduce the MexXY-OprM pump and become multidrug resistant, which accounts for the high prevalence of MexXY-OprM mutants in the clinical setting.

scholarly journals RNA chaperones Hfq and ProQ play a key role in the virulence of the plant pathogenic bacterium Dickeya dadantii

2021 ◽  
Author(s):  
Simon Leonard ◽  
Camille Villard ◽  
William Nasser ◽  
Sylvie Reverchon ◽  
Florence Hommais
Keyword(s):  
Extracellular Enzymes ◽  
Pectate Lyase ◽  
Soft Rot ◽  
Pathogenic Bacterium ◽  
Growth Defect ◽  
Dickeya Dadantii ◽  
Genes Encoding ◽  
Lyase Activity ◽  
Rna Chaperones ◽  
Post Transcriptional Regulation

Dickeya dadantii is an important pathogenic bacterium that infects a number of crops including potato and chicory. While extensive works have been carried out on the control of the transcription of its genes encoding the main virulence functions, little information is available on the post-transcriptional regulation of these functions. We investigated the involvement of the RNA chaperones Hfq and ProQ in the production of the main D. dadantii virulence functions. Phenotypic assays on the hfq and proQ mutants showed that inactivation of hfq resulted in a growth defect, a modified capacity for biofilm formation and strongly reduced motility, and in the production of degradative extracellular enzymes (proteases, cellulase and pectate lyases). Accordingly, the hfq mutant failed to cause soft rot on chicory leaves. The proQ mutant had reduced resistance to osmotic stress, reduced extracellular pectate lyase activity compared to the wild-type strain, and reduced virulence on chicory leaves. Most of the phenotypes of the hfq and proQ mutants were related to the low amounts of mRNA of the corresponding virulence factors. Complementation of the double mutant hfq-proQ by each individual protein and cross-complementation of each chaperone suggested that they might exert their effects via partially overlapping but different sets of targets. Overall, it clearly appeared that the two Hfq and ProQ RNA chaperones are important regulators of pathogenicity in D. dadantii. This underscores that virulence genes are regulated post transcriptionally by non-coding RNAs.

scholarly journals Characterization of a New Bacteriocin Operon in Sakacin P-Producing Lactobacillus sakei, Showing Strong Translational Coupling between the Bacteriocin and Immunity Genes

2005 ◽  
Vol 71 (7) ◽  
pp. 3565-3574 ◽  
Author(s):  
Geir Mathiesen ◽  
Kathrin Huehne ◽  
Lothar Kroeckel ◽  
Lars Axelsson ◽  
Vincent G. H. Eijsink
Keyword(s):  
Antimicrobial Properties ◽  
Gene Clusters ◽  
Inducible Promoter ◽  
Leader Peptide ◽  
Lactobacillus Sakei ◽  
Translational Coupling ◽  
Immunity Protein ◽  
Immunity Genes ◽  
Genes Encoding

ABSTRACT Previous studies of genes involved in the production of sakacin P by Lactobacillus sakei Lb674 revealed the presence of an inducible promoter downstream of the known spp gene clusters. We show here that this promoter drives the expression of an operon consisting of a bacteriocin gene (sppQ), a cognate immunity gene (spiQ), another gene with an unknown function (orf4), and a pseudoimmunity gene containing a frameshift mutation (orf5). The leader peptide of the new one-peptide bacteriocin sakacin Q contains consensus elements that are typical for so-called “double-glycine” leader peptides. The mature bacteriocin shows weak similarity to the BrcA peptide of the two-peptide bacteriocin brochocin C. Sakacin Q has an antimicrobial spectrum that differs from that of sakacin P, thus expanding the antimicrobial properties of the producer strain. The genes encoding sakacin Q and its cognate immunity protein showed strong translational coupling, which was investigated in detail by analyzing the properties of a series of β-glucuronidase fusions. Our results provide experimental evidence that production of the bacteriocin and production of the cognate immunity protein are tightly coregulated at the translational level.

scholarly journals Isolation and characterization of two genes encoding proteases associated with the mycelium of Streptomyces lividans 66.

1995 ◽  
Vol 177 (21) ◽  
pp. 6033-6040 ◽  
Author(s):  
C Binnie ◽  
M J Butler ◽  
J S Aphale ◽  
R Bourgault ◽  
M A DiZonno ◽  
...  
Keyword(s):  
Streptomyces Lividans ◽  
Isolation And Characterization ◽  
Genes Encoding

scholarly journals Tylosin Resistance in Arcanobacterium pyogenes Is Encoded by an Erm X Determinant

2003 ◽  
Vol 47 (11) ◽  
pp. 3519-3524 ◽  
Author(s):  
B. Helen Jost ◽  
Adam C. Field ◽  
Hien T. Trinh ◽  
J. Glenn Songer ◽  
Stephen J. Billington
Keyword(s):  
Antimicrobial Agents ◽  
Growth Promotion ◽  
The United States ◽  
Feedlot Cattle ◽  
Leader Peptide ◽  
Nucleotide Sequencing ◽  
Reading Frame ◽  
Constitutive Resistance ◽  
Genes Encoding ◽  
Arcanobacterium Pyogenes

ABSTRACT Arcanobacterium pyogenes, a commensal on the mucous membranes of many economically important animal species, is also a pathogen, causing abscesses of the skin, joints, and visceral organs as well as mastitis and abortion. In food animals, A. pyogenes is exposed to antimicrobial agents used for growth promotion, prophylaxis, and therapy, notably tylosin, a macrolide antibiotic used extensively for the prevention of liver abscessation in feedlot cattle in the United States. Of 48 A. pyogenes isolates, 11 (22.9%) exhibited inducible or constitutive resistance to tylosin (MIC of ≥128 μg/ml). These isolates also exhibited resistance to other macrolide and lincosamide antibiotics, suggesting a macrolide-lincosamide resistance phenotype. Of the 11 resistant isolates, genomic DNA from nine hybridized to an erm(X)-specific probe. Cloning and nucleotide sequencing of the A. pyogenes erm(X) gene indicated that it was >95% similar to erm(X) genes from Corynebacterium and Propionibacterium spp. Eight of the erm(X)-containing A. pyogenes isolates exhibited inducible tylosin resistance, which was consistent with the presence of a putative leader peptide upstream of the erm(X) open reading frame. For at least one A. pyogenes isolate, 98-4277-2, erm(X) was present on a plasmid, pAP2, and was associated with the insertion sequence IS6100. pAP2 also carried genes encoding the repressor-regulated tetracycline efflux system determinant Tet 33. The repA gene from pAP2 was nonfunctional in Escherichia coli and at least one A. pyogenes isolate, suggesting that there may be host-encoded factors required for replication of this plasmid.

scholarly journals RNA Chaperones Hfq and ProQ Play a Key Role in the Virulence of the Plant Pathogenic Bacterium Dickeya dadantii

2021 ◽  
Vol 12 ◽  
Author(s):  
Simon Leonard ◽  
Camille Villard ◽  
William Nasser ◽  
Sylvie Reverchon ◽  
Florence Hommais
Keyword(s):  
Extracellular Enzymes ◽  
Pectate Lyase ◽  
Soft Rot ◽  
Pathogenic Bacterium ◽  
Growth Defect ◽  
Dickeya Dadantii ◽  
Genes Encoding ◽  
Lyase Activity ◽  
Rna Chaperones ◽  
Post Transcriptional Regulation

Dickeya dadantii is an important pathogenic bacterium that infects a number of crops including potato and chicory. While extensive works have been carried out on the control of the transcription of its genes encoding the main virulence functions, little information is available on the post-transcriptional regulation of these functions. We investigated the involvement of the RNA chaperones Hfq and ProQ in the production of the main D. dadantii virulence functions. Phenotypic assays on the hfq and proQ mutants showed that inactivation of hfq resulted in a growth defect, a modified capacity for biofilm formation and strongly reduced motility, and in the production of degradative extracellular enzymes (proteases, cellulase, and pectate lyases). Accordingly, the hfq mutant failed to cause soft rot on chicory leaves. The proQ mutant had reduced resistance to osmotic stress, reduced extracellular pectate lyase activity compared to the wild-type strain, and reduced virulence on chicory leaves. Most of the phenotypes of the hfq and proQ mutants were related to the low amounts of mRNA of the corresponding virulence factors. Complementation of the double mutant hfq-proQ by each individual protein and cross-complementation of each chaperone suggested that they might exert their effects via partially overlapping but different sets of targets. Overall, it clearly appeared that the two Hfq and ProQ RNA chaperones are important regulators of pathogenicity in D. dadantii. This underscores that virulence genes are regulated post-transcriptionally by non-coding RNAs.

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