An Esterase Gene from Lactobacillus casei Cotranscribed with Genes Encoding a Phosphoenolpyruvate:Sugar Phosphotransferase System and Regulated by a LevR-Like Activator and σ54 Factor

2004 ◽  
Vol 8 (2) ◽  
pp. 117-128 ◽  
Author(s):  
María J. Yebra ◽  
Rosa Viana ◽  
Vicente Monedero ◽  
Josef Deutscher ◽  
Gaspar Pérez-Martínez
Keyword(s):  
Lactobacillus Casei ◽  
Phosphotransferase System ◽  
Genes Encoding ◽  
Esterase Gene

PTS-Mediated Regulation of the Transcription Activator MtlR from Different Species: Surprising Differences despite Strong Sequence Conservation

2015 ◽  
Vol 25 (2-3) ◽  
pp. 94-105 ◽  
Author(s):  
Philippe Joyet ◽  
Meriem Derkaoui ◽  
Houda Bouraoui ◽  
Josef Deutscher
Keyword(s):  
Bacillus Subtilis ◽  
Lactobacillus Casei ◽  
Sequence Conservation ◽  
Geobacillus Stearothermophilus ◽  
Transcription Activator ◽  
Phosphotransferase System ◽  
Transcription Regulator ◽  
Regulatory Domains ◽  
Genes Encoding ◽  
Enzyme I

The hexitol <smlcap>D</smlcap>-mannitol is transported by many bacteria via a phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS). In most Firmicutes, the transcription activator MtlR controls the expression of the genes encoding the <smlcap>D</smlcap>-mannitol-specific PTS components and <smlcap>D</smlcap>-mannitol-1-P dehydrogenase. MtlR contains an N-terminal helix-turn-helix motif followed by an Mga-like domain, two PTS regulation domains (PRDs), an EIIB<sup>Gat</sup>- and an EIIA<sup>Mtl</sup>-like domain. The four regulatory domains are the target of phosphorylation by PTS components. Despite strong sequence conservation, the mechanisms controlling the activity of MtlR from <i>Lactobacillus casei</i>, <i>Bacillus subtilis</i> and <i>Geobacillus stearothermophilus</i> are quite different. Owing to the presence of a tyrosine in place of the second conserved histidine (His) in PRD2, <i>L. casei</i> MtlR is not phosphorylated by Enzyme I (EI) and HPr. When the corresponding His in PRD2 of MtlR from <i>B. subtilis</i> and <i>G. stearothermophilus</i> was replaced with alanine, the transcription regulator was no longer phosphorylated and remained inactive. Surprisingly, <i>L. casei</i> MtlR functions without phosphorylation in PRD2 because in a <i>ptsI</i> (EI) mutant MtlR is constitutively active. EI inactivation prevents not only phosphorylation of HPr, but also of the PTS<sup>Mtl</sup> components, which inactivate MtlR by phosphorylating its EIIB<sup>Gat</sup>- or EIIA<sup>Mtl</sup>-like domain. This explains the constitutive phenotype of the <i>ptsI</i> mutant. The absence of EIIB<sup>Mtl</sup>-mediated phosphorylation leads to induction of the <i>L. casei</i><i>mtl </i>operon. This mechanism resembles <i>mtlARFD</i> induction in <i>G. stearothermophilus</i>, but differs from EIIA<sup>Mtl</sup>-mediated induction in <i>B. subtilis</i>. In contrast to <i>B. subtilis</i> MtlR, <i>L. casei</i> MtlR activation does not require sequestration to the membrane via the unphosphorylated EIIB<sup>Mtl</sup> domain.

Comprehensive genomics depict accessory genes encoding pathogenicity and biofilm determinants in Enterococcus faecalis

2021 ◽  
Vol 16 (3) ◽  
pp. 175-184
Author(s):  
Karthika Suryaletha ◽  
Sivakumar K Chandrika ◽  
Sabu Thomas
Keyword(s):  
Enterococcus Faecalis ◽  
Signaling System ◽  
Phosphotransferase System ◽  
Related Factors ◽  
Polysaccharide Lyase ◽  
Factors Associated ◽  
Analysis Methodology ◽  
Accessory Genes ◽  
Genes Encoding ◽  
Phage Proteins

Aim: Enterococcus faecalis is a leading nosocomial pathogen in biofilm-associated polymicrobial infections. The study aims to understand pathogenicity and biofilm determinants of the pathogen by genome analysis. Methodology: Genome sequencing of a strong biofilm forming clinical isolate Enterococcus faecalis SK460 devoid of Fsr quorum-signaling system, was performed and comparative genomics was carried out among a set of pathogenic biofilm formers and nonpathogenic weak biofilm formers. Results: Analysis revealed a pool of virulence and adhesion related factors associated with pathogenicity. Absence of CRISPR-Cas system facilitated acquisition of pheromone responsive plasmid, pathogenicity island and phages. Comprehensive analysis identified a subset of accessory genes encoding polysaccharide lyase, sugar phosphotransferase system, phage proteins and transcriptional regulators exclusively in pathogenic biofilm formers. Conclusion: The study identified a set of genes specific to pathogenic biofilm formers and these can act as targets which in turn help to develop future treatment endeavors against enterococcal infections.

scholarly journals Two Gene Clusters Coordinate Galactose and Lactose Metabolism in Streptococcus gordonii

2012 ◽  
Vol 78 (16) ◽  
pp. 5597-5605 ◽  
Author(s):  
Lin Zeng ◽  
Nicole C. Martino ◽  
Robert A. Burne
Keyword(s):  
Gene Clusters ◽  
Selective Advantage ◽  
Streptococcus Gordonii ◽  
Phosphotransferase System ◽  
Content Type ◽  
High Affinity ◽  
Oral Biofilms ◽  
Genes Encoding ◽  
Complex Regulation ◽  
Galactose Utilization

ABSTRACTStreptococcus gordoniiis an early colonizer of the human oral cavity and an abundant constituent of oral biofilms. Two tandemly arranged gene clusters, designatedlacandgal, were identified in theS. gordoniiDL1 genome, which encode genes of the tagatose pathway (lacABCD) and sugar phosphotransferase system (PTS) enzyme II permeases. Genes encoding a predicted phospho-β-galactosidase (LacG), a DeoR family transcriptional regulator (LacR), and a transcriptional antiterminator (LacT) were also present in the clusters. Growth and PTS assays supported that the permease designated EIILactransports lactose and galactose, whereas EIIGaltransports galactose. The expression of the gene for EIIGalwas markedly upregulated in cells growing on galactose. Using promoter-catfusions, a role for LacR in the regulation of the expressions of both gene clusters was demonstrated, and thegalcluster was also shown to be sensitive to repression by CcpA. The deletion oflacTcaused an inability to grow on lactose, apparently because of its role in the regulation of the expression of the genes for EIILac, but had little effect on galactose utilization.S. gordoniimaintained a selective advantage overStreptococcus mutansin a mixed-species competition assay, associated with its possession of a high-affinity galactose PTS, althoughS. mutanscould persist better at low pHs. Collectively, these results support the concept that the galactose and lactose systems ofS. gordoniiare subject to complex regulation and that a high-affinity galactose PTS may be advantageous whenS. gordoniiis competing against the caries pathogenS. mutansin oral biofilms.

scholarly journals Control of chitin and N-acetylglucosamine utilization in Saccharopolyspora erythraea

Microbiology ◽  
2014 ◽  
Vol 160 (9) ◽  
pp. 1914-1928 ◽  
Author(s):  
Chengheng Liao ◽  
Sébastien Rigali ◽  
Cuauhtemoc Licona Cassani ◽  
Esteban Marcellin ◽  
Lars Keld Nielsen ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Streptomyces Coelicolor ◽  
Saccharopolyspora Erythraea ◽  
Phosphotransferase System ◽  
Nutrient Source ◽  
Intracellular Degradation ◽  
Rare Actinomycetes ◽  
Genes Encoding ◽  
Or Genes ◽  
Model Strain

Chitin degradation and subsequent N-acetylglucosamine (GlcNAc) catabolism is thought to be a common trait of a large majority of actinomycetes. Utilization of aminosugars had been poorly investigated outside the model strain Streptomyces coelicolor A3(2), and we examined here the genetic setting of the erythromycin producer Saccharopolyspora erythraea for GlcNAc and chitin utilization, as well as the transcriptional control thereof. Sacch. erythraea efficiently utilize GlcNAc most likely via the phosphotransferase system (PTSGlcNAc); however, this strain is not able to grow when chitin or N,N′-diacetylchitobiose [(GlcNAc)2] is the sole nutrient source, despite a predicted extensive chitinolytic system (chi genes). The inability of Sacch. erythraea to utilize chitin and (GlcNAc)2 is probably because of the loss of genes encoding the DasABC transporter for (GlcNAc)2 import, and genes for intracellular degradation of (GlcNAc)2 by β-N-acetylglucosaminidases. Transcription analyses revealed that in Sacch. erythraea all putative chi and GlcNAc utilization genes are repressed by DasR, whereas in Strep. coelicolor DasR displayed either activating or repressing functions whether it targets genes involved in the polymer degradation or genes for GlcNAc dimer and monomer utilization, respectively. A transcriptomic analysis further showed that GlcNAc not only activates the transcription of GlcNAc catabolism genes but also activates chi gene expression, as opposed to the previously reported GlcNAc-mediated catabolite repression in Strep. coelicolor. Finally, synteny exploration revealed an identical genetic background for chitin utilization in other rare actinomycetes, which suggests that screening procedures that used only the chitin-based protocol for selective isolation of antibiotic-producing actinomycetes could have missed the isolation of many industrially promising strains.

scholarly journals Regulation of Lactobacillus casei Sorbitol Utilization Genes Requires DNA-Binding Transcriptional Activator GutR and the Conserved Protein GutM

2008 ◽  
Vol 74 (18) ◽  
pp. 5731-5740 ◽  
Author(s):  
Cristina Alcántara ◽  
Luz Adriana Sarmiento-Rubiano ◽  
Vicente Monedero ◽  
Josef Deutscher ◽  
Gaspar Pérez-Martínez ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Sequence Comparison ◽  
Promoter Region ◽  
Lactobacillus Casei ◽  
Transcriptional Regulator ◽  
Transcriptional Activator ◽  
Regulation Mechanism ◽  
Phosphotransferase System ◽  
Footprint Analysis ◽  
Operon Expression

ABSTRACT Sequence analysis of the five genes (gutRMCBA) downstream from the previously described sorbitol-6-phosphate dehydrogenase-encoding Lactobacillus casei gutF gene revealed that they constitute a sorbitol (glucitol) utilization operon. The gutRM genes encode putative regulators, while the gutCBA genes encode the EIIC, EIIBC, and EIIA proteins of a phosphoenolpyruvate-dependent sorbitol phosphotransferase system (PTSGut). The gut operon is transcribed as a polycistronic gutFRMCBA messenger, the expression of which is induced by sorbitol and repressed by glucose. gutR encodes a transcriptional regulator with two PTS-regulated domains, a galactitol-specific EIIB-like domain (EIIBGat domain) and a mannitol/fructose-specific EIIA-like domain (EIIAMtl domain). Its inactivation abolished gut operon transcription and sorbitol uptake, indicating that it acts as a transcriptional activator. In contrast, cells carrying a gutB mutation expressed the gut operon constitutively, but they failed to transport sorbitol, indicating that EIIBCGut negatively regulates GutR. A footprint analysis showed that GutR binds to a 35-bp sequence upstream from the gut promoter. A sequence comparison with the presumed promoter region of gut operons from various firmicutes revealed a GutR consensus motif that includes an inverted repeat. The regulation mechanism of the L. casei gut operon is therefore likely to be operative in other firmicutes. Finally, gutM codes for a conserved protein of unknown function present in all sequenced gut operons. A gutM mutant, the first constructed in a firmicute, showed drastically reduced gut operon expression and sorbitol uptake, indicating a regulatory role also for GutM.

scholarly journals Streptococcal phosphotransferase system imports unsaturated hyaluronan disaccharide derived from host extracellular matrices

2018 ◽  
Author(s):  
Sayoko Oiki ◽  
Yusuke Nakamichi ◽  
Yukie Maruyama ◽  
Bunzo Mikami ◽  
Kousaku Murata ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Molecular System ◽  
Bacterial Species ◽  
Three Dimensional ◽  
Amino Sugar ◽  
Extracellular Matrices ◽  
Dimensional Structure ◽  
Phosphotransferase System ◽  
Streptobacillus Moniliformis ◽  
Genes Encoding

ABSTRACTCertain bacterial species target the polysaccharide glycosaminoglycans (GAGs) of animal extracellular matrices for colonization and/or infection. GAGs such as hyaluronan and chondroitin sulfate consist of repeating disaccharide units of uronate and amino sugar residues, and are depolymerized to unsaturated disaccharides by bacterial extracellular or cell-surface polysaccharide lyase. The disaccharides are degraded and metabolized by cytoplasmic enzymes such as unsaturated glucuronyl hydrolase, isomerase, and reductase. The genes encoding these enzymes are assembled to form a GAG genetic cluster. Here, we demonstrate theStreptococcus agalactiaephosphotransferase system (PTS) for import of unsaturated hyaluronan disaccharide.S. agalactiaeNEM316 was found to depolymerize and assimilate hyaluronan, whereas its mutant with a disruption in PTS genes included in the GAG cluster was unable to grow on hyaluronan, while retaining the ability to depolymerize hyaluronan. Using toluene-treated wild-type cells, the PTS import activity of unsaturated hyaluronan disaccharide was significantly higher than that observed in the absence of the substrate. In contrast, the PTS mutant was unable to import unsaturated hyaluronan disaccharide, indicating that the corresponding PTS is the only importer of fragmented hyaluronan, which is suitable for PTS to phosphorylate the substrate at the C-6 position. The three-dimensional structure of streptococcal EIIA, one of the PTS components, was found to contain a Rossman-fold motif by X-ray crystallization. Docking of EIIA with another component EIIB by modeling provided structural insights into the phosphate transfer mechanism. This study is the first to identify the substrate (unsaturated hyaluronan disaccharide) recognized and imported by the streptococcal PTS.IMPORTANCE (118/120 words)The PTS identified in this work imports sulfate group-free unsaturated hyaluronan disaccharide as a result of the phosphorylation of the substrate at the C-6 position.S. agalactiaecan be indigenous to animal hyaluronan-rich tissues owing to the bacterial molecular system for fragmentation, import, degradation, and metabolism of hyaluronan. Distinct from hyaluronan, most GAGs, which are sulfated at the C-6 position, are unsuitable for PTS due to its inability to phosphorylate the substrate. More recently, we have identified a solute-binding protein-dependent ABC transporter in a pathogenicStreptobacillus moniliformisas an importer of sulfated and non-sulfated fragmented GAGs without any substrate modification. Our findings regarding PTS and ABC transporter shed light on bacterial clever colonization/infection system targeting various animal GAGs.

scholarly journals Genome-wide transcriptomic analysis of n-caproic acid production in Ruminococcaceae bacterium CPB6 with lactate supplementation

2020 ◽  
Author(s):  
Yong Tao ◽  
Shaowen Lu ◽  
Yi Wang ◽  
Cuicui Wei ◽  
Hong Jin ◽  
...  
Keyword(s):  
Stationary Phases ◽  
Expression Patterns ◽  
Caproic Acid ◽  
Transcriptional Analysis ◽  
Chain Elongation ◽  
Transcriptional Level ◽  
Phosphotransferase System ◽  
Oxidation Pathway ◽  
Genome Wide ◽  
Genes Encoding

Abstract Background n-Caproic acid (CA) is gaining increased attention due to its high value as a chemical feedstock. Ruminococcaceae bacterium strain CPB6 is an anaerobic mesophilic bacterium that is highly prolific in its ability to perform chain elongation of lactate to CA. However, little is known about the genome-wide transcriptional analysis of strain CPB6 for CA production triggered by the supplementation of exogenous lactate. Results In this study, 0.5% lactate was supplemented into the fermentation with Ruminococcaceae bacterium CPB6 for CA production. Compared to the control (without lactate supplementation), lactate supplementation led to earlier CA production and higher final CA titer and productivity. Transcriptional analysis was carried out using RNA-Seq for the culture with and without lactate supplementation (two groups) at growth and stationary phases, respectively. It has been indicated that 295 genes whose changes in expression patterns were substrate and/or growth dependent. These genes cover crucial functional categories. Specifically, 5 genes responsible for the reverse β-oxidation pathway, 11 genes encoding ATP-binding cassette (ABC) transporters, 6 genes encoding substrate-binding protein (SBP) and 4 genes encoding phosphotransferase system (PTS) transporters were strikingly upregulated in response to the addition of lactate. These genes would be candidates for future studies aiming at understanding the regulatory mechanism of lactate conversion into CA, as well as for the improvement of CA production in strain CPB6. Conclusions This study suggested that lactate supplementation can promote CA production by altering the expression patterns of genes involved in the essential metabolic pathways, such as central pyruvate metabolism, the reverse β-oxidation pathway, ABC and PTS transports. The findings presented herein reveal unique insights into the biomolecular effects of lactate on CA production at the gene transcriptional level.

scholarly journals Malic Enzyme and Malolactic Enzyme Pathways Are Functionally Linked but Independently Regulated in Lactobacillus casei BL23

2013 ◽  
Vol 79 (18) ◽  
pp. 5509-5518 ◽  
Author(s):  
José María Landete ◽  
Sergi Ferrer ◽  
Vicente Monedero ◽  
Manuel Zúñiga
Keyword(s):  
Carbon Source ◽  
Gene Cluster ◽  
Malic Enzyme ◽  
Lactobacillus Casei ◽  
Growth Defect ◽  
Two Component System ◽  
Content Type ◽  
Malolactic Enzyme ◽  
Genes Encoding ◽  
Malate Metabolism

ABSTRACTLactobacillus caseiis the only lactic acid bacterium in which two pathways forl-malate degradation have been described: the malolactic enzyme (MLE) and the malic enzyme (ME) pathways. Whereas the ME pathway enablesL. caseito grow onl-malate, MLE does not support growth. Themlegene cluster consists of three genes encoding MLE (mleS), the putativel-malate transporter MleT, and the putative regulator MleR. Themaegene cluster consists of four genes encoding ME (maeE), the putative transporter MaeP, and the two-component system MaeKR. Since both pathways compete for the same substrate, we sought to determine whether they are coordinately regulated and their role inl-malate utilization as a carbon source. Transcriptional analyses revealed that themleandmaegenes are independently regulated and showed that MleR acts as an activator and requires internalization ofl-malate to induce the expression ofmlegenes. Notwithstanding, bothl-malate transporters were required for maximall-malate uptake, although only anmleTmutation caused a growth defect onl-malate, indicating its crucial role inl-malate metabolism. However, inactivation of MLE resulted in higher growth rates and higher final optical densities onl-malate. The limited growth onl-malate of the wild-type strain was correlated to a rapid degradation of the availablel-malate tol-lactate, which cannot be further metabolized. Taken together, our results indicate thatL. caseil-malate metabolism is not optimized for utilization ofl-malate as a carbon source but for deacidification of the medium by conversion ofl-malate intol-lactate via MLE.

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