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Effects of Different Stress Parameters on Growth and on Oleuropein-Degrading Abilities of Lactiplantibacillus plantarum Strains Selected as Tailored Starter Cultures for Naturally Table Olives. Microorganisms 2020; 8:microorganisms8101607. [PMID: 33086685 PMCID: PMC7590217 DOI: 10.3390/microorganisms8101607] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/13/2020] [Accepted: 10/16/2020] [Indexed: 01/08/2023] Open
Abstract
The use of β-glucosidase positive strains, as tailored-starter cultures for table olives fermentation, is a useful biotechnological tool applied to accelerate the debittering process. Nowadays, strains belonging to Lactiplantibacillus plantarum species are selected for their high versatility and tolerance to stress conditions. The present study investigated the effect of different stress factors (pH, temperature and NaCl) on growth and on oleuropein-degrading abilities of selected L. plantarum strains. In addition, the presence of the beta-glucosidase gene was investigated by applying a PCR based approach. Results revealed that, overall, the performances of the tested strains appeared to be robust toward the different stressors. However, the temperature of 16 °C significantly affected the growth performance of the strains both singularly and in combination with other stressing factors since it prolongs the latency phase and reduces the maximum growth rate of strains. Similarly, the oleuropein degradation was mainly affected by the low temperature, especially in presence of low salt content. Despite all strains displayed the ability to reduce the oleuropein content, the beta-glucosidase gene was detected in five out of the nine selected strains, demonstrating that the ability to hydrolyze the oleuropein is not closely related to the presence of beta-glucosidase. Data of the present study suggest that is extremely important to test the technological performances of strains at process conditions in order to achieve a good selection of tailored starter cultures for table olives.
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Panwar D, Kapoor M. Transcriptional analysis of galactomannooligosaccharides utilization by Lactobacillus plantarum WCFS1. Food Microbiol 2020; 86:103336. [DOI: 10.1016/j.fm.2019.103336] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 09/12/2019] [Accepted: 09/13/2019] [Indexed: 02/06/2023]
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LacR is a repressor of lacABCD and LacT is an activator of lacTFEG, constituting the lac gene cluster in Streptococcus pneumoniae. Appl Environ Microbiol 2014; 80:5349-58. [PMID: 24951784 DOI: 10.1128/aem.01370-14] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Comparison of the transcriptome of Streptococcus pneumoniae strain D39 grown in the presence of either lactose or galactose with that of the strain grown in the presence of glucose revealed the elevated expression of various genes and operons, including the lac gene cluster, which is organized into two operons, i.e., lac operon I (lacABCD) and lac operon II (lacTFEG). Deletion of the DeoR family transcriptional regulator lacR that is present downstream of the lac gene cluster revealed elevated expression of lac operon I even in the absence of lactose. This suggests a function of LacR as a transcriptional repressor of lac operon I, which encodes enzymes involved in the phosphorylated tagatose pathway in the absence of lactose or galactose. Deletion of lacR did not affect the expression of lac operon II, which encodes a lactose-specific phosphotransferase. This finding was further confirmed by β-galactosidase assays with PlacA-lacZ and PlacT-lacZ in the presence of either lactose or glucose as the sole carbon source in the medium. This suggests the involvement of another transcriptional regulator in the regulation of lac operon II, which is the BglG-family transcriptional antiterminator LacT. We demonstrate the role of LacT as a transcriptional activator of lac operon II in the presence of lactose and CcpA-independent regulation of the lac gene cluster in S. pneumoniae.
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Aryl glycosidases from Lactobacillus plantarum increase antioxidant activity of phenolic compounds. J Funct Foods 2014. [DOI: 10.1016/j.jff.2014.01.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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Michlmayr H, Kneifel W. β-Glucosidase activities of lactic acid bacteria: mechanisms, impact on fermented food and human health. FEMS Microbiol Lett 2013; 352:1-10. [PMID: 24330034 DOI: 10.1111/1574-6968.12348] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 11/23/2013] [Indexed: 01/27/2023] Open
Abstract
Through the hydrolysis of plant metabolite glucoconjugates, β-glucosidase activities of lactic acid bacteria (LAB) make a significant contribution to the dietary and sensory attributes of fermented food. Deglucosylation can release attractive flavour compounds from glucosylated precursors and increases the bioavailability of health-promoting plant metabolites as well as that of dietary toxins. This review brings the current literature on LAB β-glucosidases into context by providing an overview of the nutritional implications of LAB β-glucosidase activities. Based on biochemical and genomic information, the mechanisms that are currently considered to be critical for the hydrolysis of β-glucosides by intestinal and food-fermenting LAB will also be reviewed.
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Affiliation(s)
- Herbert Michlmayr
- Christian Doppler Research Laboratory for Innovative Bran Biorefinery, Department of Food Science and Technology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
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Zago M, Lanza B, Rossetti L, Muzzalupo I, Carminati D, Giraffa G. Selection of Lactobacillus plantarum strains to use as starters in fermented table olives: Oleuropeinase activity and phage sensitivity. Food Microbiol 2013; 34:81-7. [DOI: 10.1016/j.fm.2012.11.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 09/03/2012] [Accepted: 11/16/2012] [Indexed: 11/24/2022]
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Capaldo A, Walker M, Ford C, Jiranek V. β-Glucoside metabolism in Oenococcus oeni: Cloning and characterization of the phospho-β-glucosidase CelD. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.molcatb.2010.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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8
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Capaldo A, Walker M, Ford C, Jiranek V. β-Glucoside metabolism in Oenococcus oeni: Cloning and characterisation of the phospho-β-glucosidase bglD. Food Chem 2011. [DOI: 10.1016/j.foodchem.2010.09.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Deutscher J, Francke C, Postma PW. How phosphotransferase system-related protein phosphorylation regulates carbohydrate metabolism in bacteria. Microbiol Mol Biol Rev 2007; 70:939-1031. [PMID: 17158705 PMCID: PMC1698508 DOI: 10.1128/mmbr.00024-06] [Citation(s) in RCA: 989] [Impact Index Per Article: 58.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The phosphoenolpyruvate(PEP):carbohydrate phosphotransferase system (PTS) is found only in bacteria, where it catalyzes the transport and phosphorylation of numerous monosaccharides, disaccharides, amino sugars, polyols, and other sugar derivatives. To carry out its catalytic function in sugar transport and phosphorylation, the PTS uses PEP as an energy source and phosphoryl donor. The phosphoryl group of PEP is usually transferred via four distinct proteins (domains) to the transported sugar bound to the respective membrane component(s) (EIIC and EIID) of the PTS. The organization of the PTS as a four-step phosphoryl transfer system, in which all P derivatives exhibit similar energy (phosphorylation occurs at histidyl or cysteyl residues), is surprising, as a single protein (or domain) coupling energy transfer and sugar phosphorylation would be sufficient for PTS function. A possible explanation for the complexity of the PTS was provided by the discovery that the PTS also carries out numerous regulatory functions. Depending on their phosphorylation state, the four proteins (domains) forming the PTS phosphorylation cascade (EI, HPr, EIIA, and EIIB) can phosphorylate or interact with numerous non-PTS proteins and thereby regulate their activity. In addition, in certain bacteria, one of the PTS components (HPr) is phosphorylated by ATP at a seryl residue, which increases the complexity of PTS-mediated regulation. In this review, we try to summarize the known protein phosphorylation-related regulatory functions of the PTS. As we shall see, the PTS regulation network not only controls carbohydrate uptake and metabolism but also interferes with the utilization of nitrogen and phosphorus and the virulence of certain pathogens.
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Affiliation(s)
- Josef Deutscher
- Microbiologie et Génétique Moléculaire, INRA-CNRS-INA PG UMR 2585, Thiverval-Grignon, France.
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Cote CK, Honeyman AL. Transcriptional analysis of the bglP gene from Streptococcus mutans. BMC Microbiol 2006; 6:37. [PMID: 16630357 PMCID: PMC1489936 DOI: 10.1186/1471-2180-6-37] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Accepted: 04/21/2006] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND An open reading frame encoding a putative antiterminator protein, LicT, was identified in the genomic sequence of Streptococcus mutans. A potential ribonucleic antitermination (RAT) site to which the LicT protein would potentially bind has been identified immediately adjacent to this open reading frame. The licT gene and RAT site are both located 5' to a beta-glucoside PTS regulon previously described in S. mutans that is responsible for esculin utilization in the presence of glucose. It was hypothesized that antitermination is the regulatory mechanism that is responsible for the control of the bglP gene expression, which encodes an esculin-specific PTS enzyme II. RESULTS To localize the promoter activity associated with the bglP locus, a series of transcriptional lacZ gene fusions was formed on a reporter shuttle vector using various DNA fragments from the bglP promoter region. Subsequent beta-galactosidase assays in S. mutans localized the bglP promoter region and identified putative -35 and -10 promoter elements. Primer extension analysis identified the bglP transcriptional start site. In addition, a terminated bglP transcript formed by transcriptional termination was identified via transcript mapping experiments. CONCLUSION The physical location of these genetic elements, the RAT site and the promoter regions, and the identification of a short terminated mRNA support the hypothesis that antitermination regulates the bglP transcript.
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Affiliation(s)
- Christopher K Cote
- Department of Medical Microbiology and Immunology, University of South Florida, College of Medicine, Tampa, Florida 33612, USA
- Bacteriology Division, USAMRIID, 1425 Porter Street, Fort Detrick, Frederick, MD 21702, USA
| | - Allen L Honeyman
- Department of Medical Microbiology and Immunology, University of South Florida, College of Medicine, Tampa, Florida 33612, USA
- Department of Biomedical Sciences, Texas A&M University System Health Science Center, Baylor College of Dentistry, 3302 Gaston Avenue, Dallas, Texas 75246, USA
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Andersson U, Molenaar D, Rådström P, de Vos WM. Unity in organisation and regulation of catabolic operons in Lactobacillus plantarum, Lactococcus lactis and Listeria monocytogenes. Syst Appl Microbiol 2005; 28:187-95. [PMID: 15900965 DOI: 10.1016/j.syapm.2004.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Global regulatory circuits together with more specific local regulators play a notable role when cells are adapting to environmental changes. Lactococcus lactis is a lactic acid bacterium abundant in nature fermenting most mono- and disaccharides. Comparative genomics analysis of the operons encoding the proteins and enzymes crucial for catabolism of lactose, maltose and threhalose revealed an obvious unity in operon organisation . The local regulator of each operon was located in a divergent transcriptional direction to the rest of the operon including the transport protein-encoding genes. Furthermore, in all three operons a catabolite responsive element (CRE) site was detected inbetween the gene encoding the local regulator and one of the genes encoding a sugar transport protein. It is evident that regardless of type of transport system and catabolic enzymes acting upon lactose, maltose and trehalose, respectively, Lc. lactis shows unity in both operon organisation and regulation of these catabolic operons. This knowledge was further extended to other catabolic operons in Lc. lactis and the two related bacteria Lactobacillus plantarum and Listeria monocytogenes. Thirty-nine catabolic operons responsible for degradation of sugars and sugar alcohols in Lc. lactis, Lb. plantarum and L. monocytogenes were investigated and the majority of those possessed the same organisation as the lactose, maltose and trehalose operons of Lc. lactis. Though, the frequency of CRE sites and their location varied among the bacteria. Both Lc. lactis and Lb. plantarum showed CRE sites in direct proximity to genes coding for proteins responsible for sugar uptake. However, in L. monocytogenes CRE sites were not frequently found and not in the vicinity of genes encoding transport proteins, suggesting a more local mode of regulation of the catabolic operons found and/or the use of inducer control in this bacterium.
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Affiliation(s)
- Ulrika Andersson
- Applied Microbiology, Lund Institute of Technology, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
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Bron PA, Grangette C, Mercenier A, de Vos WM, Kleerebezem M. Identification of Lactobacillus plantarum genes that are induced in the gastrointestinal tract of mice. J Bacteriol 2004; 186:5721-9. [PMID: 15317777 PMCID: PMC516819 DOI: 10.1128/jb.186.17.5721-5729.2004] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Lactobacillus plantarum is a flexible and versatile microorganism that inhabits a variety of environmental niches, including the human gastrointestinal (GI) tract. Moreover, this lactic acid bacterium can survive passage through the human or mouse stomach in an active form. To investigate the genetic background of this persistence, resolvase-based in vivo expression technology (R-IVET) was performed in L. plantarum WCFS1 by using the mouse GI tract as a model system. This approach identified 72 L. plantarum genes whose expression was induced during passage through the GI tract as compared to laboratory media. Nine of these genes encode sugar-related functions, including ribose, cellobiose, sucrose, and sorbitol transporter genes. Another nine genes encode functions involved in acquisition and synthesis of amino acids, nucleotides, cofactors, and vitamins, indicating their limited availability in the GI tract. Four genes involved in stress-related functions were identified, reflecting the harsh conditions that L. plantarum encounters in the GI tract. The four extracellular protein encoding genes identified could potentially be involved in interaction with host specific factors. The rest of the genes are part of several functionally unrelated pathways or encode (conserved) hypothetical proteins. Remarkably, a large number of the functions or pathways identified here have previously been identified in pathogens as being important in vivo during infection, strongly suggesting that survival rather than virulence is the explanation for the importance of these genes during host residence.
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Affiliation(s)
- Peter A Bron
- Wageningen Centre for Food Sciences, Ede, The Netherlands
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Kotrba P, Inui M, Yukawa H. A single V317A or V317M substitution in Enzyme II of a newly identified beta-glucoside phosphotransferase and utilization system of Corynebacterium glutamicum R extends its specificity towards cellobiose. MICROBIOLOGY (READING, ENGLAND) 2003; 149:1569-1580. [PMID: 12777497 DOI: 10.1099/mic.0.26053-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A catabolic system involved in the utilization of beta-glucosides in Corynebacterium glutamicum R and its spontaneous mutant variants allowing uptake of cellobiose were investigated. The system comprises a beta-glucoside-specific Enzyme IIBCA component (gene bglF) of the phosphotransferase system (PTS), a phospho-beta-glucosidase (bglA) and an antiterminator protein (bglG) from the BglG/SacY family of transcription regulators. The results suggest that transcription antitermination is involved in control of induction and carbon catabolite repression of bgl genes, which presumably form an operon. Functional analysis of the bglF and bglA products revealed that they are simultaneously required for uptake, phosphorylation and breakdown of methyl beta-glucoside, salicin and arbutin. Although cellobiose is not normally a substrate for BglF permease and is not utilized by C. glutamicum R, cellobiose-utilizing mutants can be obtained. The mutation responsible was mapped to the bgl locus and sequenced, and point mutations were found in codon 317 of bglF. These led to substitutions V317A and/or V317M near the putative PTS active-site H313 in the membrane-spanning IIC domain of BglF and allowed BglF to act on cellobiose. Such results strengthen the evidence that the IIC domains can be regarded as selectivity filters of the PTS.
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Affiliation(s)
- Pavel Kotrba
- Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizu, Soraku, Kyoto 619-0292, Japan
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizu, Soraku, Kyoto 619-0292, Japan
| | - Hideaki Yukawa
- Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizu, Soraku, Kyoto 619-0292, Japan
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Cote CK, Honeyman AL. The LicT protein acts as both a positive and a negative regulator of loci within the bgl regulon of Streptococcus mutans. MICROBIOLOGY (READING, ENGLAND) 2003; 149:1333-1340. [PMID: 12724394 DOI: 10.1099/mic.0.26067-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
An open reading frame (ORF) that would encode a putative antiterminator protein (LicT) of the BglG family was identified in the genomic DNA sequence of Streptococcus mutans. A DNA sequence that would encode a potential ribonucleic antiterminator (RAT) site in the mRNA at which the putative antitermination protein LicT would bind was located immediately downstream from this ORF. These putative antitermination components are upstream of a glucose-independent beta-glucoside-utilization system that is responsible for aesculin utilization by S. mutans NG8 in the presence of glucose. It was hypothesized that these putative regulatory components were an important mechanism that was involved with the controlled expression of the S. mutans bglP locus. A strain of S. mutans containing a licT : : Omega-Kan2 insertional mutation was created. This strain could not hydrolyse aesculin in the presence of glucose. The transcriptional activity associated with other genes from the bgl regulon was determined in the licT : : Omega-Kan2 genetic background using lacZ transcriptional fusions and beta-galactosidase assays to determine the effect of LicT on these loci. The LicT protein had no significant effect on the expression of the bglC promoter, a regulator of the bglA locus. However, it is essential for the optimal expression of bglP. These data correlate with the phenotype observed on aesculin plates for the S. mutans wild-type strain NG8 and the licT : : Omega-Kan2 strain. Thus, the glucose-independent beta-glucoside-specific phosphotransferase system (PTS) regulon in S. mutans relies on LicT for BglP expression and, in turn, aesculin transport in the presence of glucose. Interestingly, LicT also seems to negatively regulate the expression of the bglA promoter region. In addition, the presence of the S. mutans licT gene has been shown to be able to activate a cryptic beta-glucoside-specific operon found in Escherichia coli.
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Affiliation(s)
- Christopher K Cote
- University of South Florida College of Medicine, Department of Medical Microbiology and Immunology, Tampa, FL 33612, USA
| | - Allen L Honeyman
- University of South Florida College of Medicine, Department of Medical Microbiology and Immunology, Tampa, FL 33612, USA
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Gosalbes MAJ, Esteban CD, Pérez-Martı Nez G. In vivo effect of mutations in the antiterminator LacT in Lactobacillus casei. MICROBIOLOGY (READING, ENGLAND) 2002; 148:695-702. [PMID: 11882703 DOI: 10.1099/00221287-148-3-695] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The antiterminator LacT regulates the expression of the lactose operon in Lactobacillus casei and its activity is controlled by EII(Lac) and common PTS elements. LacT shows the two conserved domains (PRD-I and PRD-II) characteristic of the BglG antiterminator family that are implicated in the regulation of their activity, possibly by phosphorylation of conserved histidines. By site-directed mutagenesis of LacT, four histidines (His-101, His-159 in PRD-I and His-210, His-273 in PRD-II) were replaced by alanine or aspartate, mimicking non-phosphorylated and phosphorylated forms, respectively. These constructions were used to complement DeltalacT and DeltaccpA mutants. L. casei strains (DeltalacT) carrying the replacement of His-101 or His-159 by Ala showed phospho-beta-galactosidase activity in absence of the inducer (lactose), indicating that these amino acids, located in PRD-I, are essential for EII-dependent induction of the lac operon, possibly by dephosphorylation. Interestingly, these mutations rendered LacT thermosensitive. Moreover, expression of H210A and H273A (PRD-II) mutations in L. casei DeltaccpA showed that these two histidyl residues could have a role in LacT-dependent carbon catabolite repression (CCR) of this system. Overexpression of LacT in a ccpA background rendered the lac operon insensitive to CCR, but it was still sensitive to lactose induction. This suggests that the transfer of phosphate groups from PTS elements, which controls these two regulatory processes (CCR and substrate induction), could have different affinity for PRD-I and PRD-II histidines.
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Affiliation(s)
- Marı A J Gosalbes
- Departamento de Biotecnologı́a, Instituto de Agroquı́mica y Tecnologı́a de Alimentos (CSIC), Polı́gono de la Coma s/n, Apartado de correos (PO Box) 73, 46100-Burjassot, Valencia, Spain1
| | - Carlos D Esteban
- Departamento de Biotecnologı́a, Instituto de Agroquı́mica y Tecnologı́a de Alimentos (CSIC), Polı́gono de la Coma s/n, Apartado de correos (PO Box) 73, 46100-Burjassot, Valencia, Spain1
| | - Gaspar Pérez-Martı Nez
- Departamento de Biotecnologı́a, Instituto de Agroquı́mica y Tecnologı́a de Alimentos (CSIC), Polı́gono de la Coma s/n, Apartado de correos (PO Box) 73, 46100-Burjassot, Valencia, Spain1
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Cote CK, Honeyman AL. The transcriptional regulation of the Streptococcus mutans bgl regulon. ORAL MICROBIOLOGY AND IMMUNOLOGY 2002; 17:1-8. [PMID: 11860549 DOI: 10.1046/j.0902-0055.2001.00087.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A beta-glucoside utilization regulon recently isolated from Streptococcus mutans has been shown to contain genes involved in beta-glucoside hydrolysis and a putative regulator. The bglP gene encodes a beta-glucoside-specific enzyme II (EII) component of the phosphoenolpyruvate-dependent phosphotransferase system, the bglC gene encodes a putative transcriptional regulator, and the bglA gene encodes a putative phospho-beta-glucosidase. To investigate the transcriptional activity of these genes, the putative promoter regions of the bglP, bglC and bglA genes were fused with the E. coli lacZ reporter gene. The resultant reporter plasmids were used to monitor the transcriptional activity of these loci in S. mutans. The results illustrate that these genes are not repressed by glucose in the presence of an inducing beta-glucoside, esculin, to the levels of expression observed in the absence of esculin. Therefore, these loci are not subject to catabolite repression by glucose to noninduced levels of expression. The bglC gene product was determined to be a positive transcriptional regulator of the bglA gene but does not regulate the expression of the bglP gene. Thus, regulation of these loci requires different and multiple control mechanisms.
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Affiliation(s)
- C K Cote
- Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, 12901 Bruce B. Downs Boulevard, Tampa, FL 33612, USA
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Muscariello L, Marasco R, De Felice M, Sacco M. The functional ccpA gene is required for carbon catabolite repression in Lactobacillus plantarum. Appl Environ Microbiol 2001; 67:2903-7. [PMID: 11425700 PMCID: PMC92959 DOI: 10.1128/aem.67.7.2903-2907.2001] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report the characterization of the ccpA gene of Lactobacillus plantarum, coding for catabolite control protein A. The gene is linked to the pepQ gene, encoding a proline peptidase, in the order ccpA-pepQ, with the two genes transcribed in tandem from the same strand as distinct transcriptional units. Two ccpA transcription start sites corresponding to two functional promoters were found, expression from the upstream promoter being autogenously regulated through a catabolite-responsive element (cre) sequence overlapping the upstream +1 site. During growth on ribose, the upstream promoter showed maximal expression, while growth on glucose led to transcription from the downstream promoter. In a ccpA mutant strain, the gene was transcribed mainly from the upstream promoter in both repressing and non repressing conditions. Expression of two enzyme activities, beta-glucosidase and beta-galactosidase, was relieved from carbon catabolite repression in the ccpA mutant strain. In vivo footprinting analysis of the catabolite-controlled bglH gene regulatory region in the ccpA mutant strain showed loss of protection of the cre under repressing conditions.
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Affiliation(s)
- L Muscariello
- Istituto Internazionale di Genetica e Biofisica, Consiglio Nazionale delle Ricerche, 80125 Naples, Italy
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Kotrba P, Inui M, Yukawa H. Bacterial phosphotransferase system (PTS) in carbohydrate uptake and control of carbon metabolism. J Biosci Bioeng 2001. [DOI: 10.1016/s1389-1723(01)80308-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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