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El Rayes J, Rodríguez-Alonso R, Collet JF. Lipoproteins in Gram-negative bacteria: new insights into their biogenesis, subcellular targeting and functional roles. Curr Opin Microbiol 2021; 61:25-34. [PMID: 33667939 DOI: 10.1016/j.mib.2021.02.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023]
Abstract
Bacterial lipoproteins are globular proteins anchored to a membrane by a lipid moiety. By discovering new functions carried out by lipoproteins, recent research has highlighted the crucial roles played by these proteins in the cell envelope of Gram-negative bacteria. Here, after discussing the wide range of activities carried out by lipoproteins in the model bacterium Escherichia coli, we review new insights into the essential mechanisms involved in lipoprotein maturation, sorting and targeting to their final destination. A special attention will also be given to the recent identification of lipoproteins on the surface of E. coli and of other bacteria. The renewed interest in lipoproteins is driven by the need to identify novel targets for antibiotic development.
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Affiliation(s)
- Jessica El Rayes
- WELBIO, Avenue Hippocrate 75, 1200 Brussels, Belgium; de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 75, 1200 Brussels, Belgium
| | - Raquel Rodríguez-Alonso
- WELBIO, Avenue Hippocrate 75, 1200 Brussels, Belgium; de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 75, 1200 Brussels, Belgium
| | - Jean-François Collet
- WELBIO, Avenue Hippocrate 75, 1200 Brussels, Belgium; de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 75, 1200 Brussels, Belgium.
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2
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Lipoprotein N-Acylation in Staphylococcus aureus Is Catalyzed by a Two-Component Acyl Transferase System. mBio 2020; 11:mBio.01619-20. [PMID: 32723923 PMCID: PMC7387801 DOI: 10.1128/mbio.01619-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although it has long been known that S. aureus forms triacylated Lpps, a lack of homologs to known N-acylation genes found in Gram-negative bacteria has until now precluded identification of the genes responsible for this Lpp modification. Here, we demonstrate N-terminal Lpp acylation and chemotype conversion to the tri-acylated state is directed by a unique acyl transferase system encoded by two noncontiguous staphylococci genes (lnsAB). Since triacylated Lpps stimulate TLR2 more weakly than their diacylated counterparts, Lpp N-acylation is an important TLR2 immunoevasion factor for determining tolerance or nontolerance in niches such as in the skin microbiota. The discovery of the LnsAB system expands the known diversity of Lpp biosynthesis pathways and acyl transfer biochemistry in bacteria, advances our understanding of Lpp structural heterogeneity, and helps differentiate commensal and noncommensal microbiota. Bacterial lipoproteins (Lpps) are a class of membrane-associated proteins universally distributed among all bacteria. A characteristic N-terminal cysteine residue that is variably acylated anchors C-terminal globular domains to the extracellular surface, where they serve numerous roles, including in the capture and transport of essential nutrients. Lpps are also ligands for the Toll-like receptor 2 (TLR2) family, a key component of the innate immune system tasked with bacterial recognition. While Lpp function is conserved in all prokaryotes, structural heterogeneity in the N-terminal acylation state is widespread among Firmicutes and can differ between otherwise closely related species. In this study, we identify a novel two-gene system that directs the synthesis of N-acylated Lpps in the commensal and opportunistic pathogen subset of staphylococci. The two genes, which we have named the lipoprotein N-acylation transferase system (Lns), bear no resemblance to previously characterized N-terminal Lpp tailoring enzymes. LnsA (SAOUHSC_00822) is an NlpC/P60 superfamily enzyme, whereas LnsB (SAOHSC_02761) has remote homology to the CAAX protease and bacteriocin-processing enzyme (CPBP) family. Both LnsA and LnsB are together necessary and alone sufficient for N-acylation in Staphylococcus aureus and convert the Lpp chemotype from diacyl to triacyl when heterologously expressed in Listeria monocytogenes. Acquisition of lnsAB decreases TLR2-mediated detection of S. aureus by nearly 10-fold and shifts the activated TLR2 complex from TLR2/6 to TLR2/1. LnsAB thus has a dual role in attenuating TLR2 signaling in addition to a broader role in bacterial cell envelope physiology.
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Dautin N, Argentini M, Mohiman N, Labarre C, Cornu D, Sago L, Chami M, Dietrich C, de Sousa d'Auria C, Houssin C, Masi M, Salmeron C, Bayan N. Role of the unique, non-essential phosphatidylglycerol::prolipoprotein diacylglyceryl transferase (Lgt) in Corynebacterium glutamicum. MICROBIOLOGY-SGM 2020; 166:759-776. [PMID: 32490790 DOI: 10.1099/mic.0.000937] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Bacterial lipoproteins are secreted proteins that are post-translationally lipidated. Following synthesis, preprolipoproteins are transported through the cytoplasmic membrane via the Sec or Tat translocon. As they exit the transport machinery, they are recognized by a phosphatidylglycerol::prolipoprotein diacylglyceryl transferase (Lgt), which converts them to prolipoproteins by adding a diacylglyceryl group to the sulfhydryl side chain of the invariant Cys+1 residue. Lipoprotein signal peptidase (LspA or signal peptidase II) subsequently cleaves the signal peptide, liberating the α-amino group of Cys+1, which can eventually be further modified. Here, we identified the lgt and lspA genes from Corynebacterium glutamicum and found that they are unique but not essential. We found that Lgt is necessary for the acylation and membrane anchoring of two model lipoproteins expressed in this species: MusE, a C. glutamicum maltose-binding lipoprotein, and LppX, a Mycobacterium tuberculosis lipoprotein. However, Lgt is not required for these proteins' signal peptide cleavage, or for LppX glycosylation. Taken together, these data show that in C. glutamicum the association of some lipoproteins with membranes through the covalent attachment of a lipid moiety is not essential for further post-translational modification.
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Affiliation(s)
- Nathalie Dautin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.,Present address: Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Manuela Argentini
- Present address: Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012 Paris, France.,Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Niloofar Mohiman
- Present address: Curakliniken, Erikslustvägen 22, 217 73 Malmö, Sweden.,Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Cécile Labarre
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - David Cornu
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Laila Sago
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Mohamed Chami
- CBioEM lab, Biozentrum, University of Basel, 4058 Basel, Switzerland
| | - Christiane Dietrich
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Célia de Sousa d'Auria
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Christine Houssin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Muriel Masi
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Christophe Salmeron
- Present address: Observatoire Océanologique de Banyuls Sur Mer, FR 3724-Laboratoire Arago - Sorbonne Université / CNRS, France.,Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Nicolas Bayan
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
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Xia J, Feng B, Wen G, Xue W, Ma G, Zhang H, Wu S. Bacterial Lipoprotein Biosynthetic Pathway as a Potential Target for Structure-based Design of Antibacterial Agents. Curr Med Chem 2020; 27:1132-1150. [PMID: 30360704 DOI: 10.2174/0929867325666181008143411] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/31/2018] [Accepted: 08/15/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND Antibiotic resistance is currently a serious problem for global public health. To this end, discovery of new antibacterial drugs that interact with novel targets is important. The biosynthesis of lipoproteins is vital to bacterial survival and its inhibitors have shown efficacy against a range of bacteria, thus bacterial lipoprotein biosynthetic pathway is a potential target. METHODS At first, the literature that covered the basic concept of bacterial lipoprotein biosynthetic pathway as well as biochemical characterization of three key enzymes was reviewed. Then, the recently resolved crystal structures of the three enzymes were retrieved from Protein Data Bank (PDB) and the essential residues in the active sites were analyzed. Lastly, all the available specific inhibitors targeting this pathway and their Structure-activity Relationship (SAR) were discussed. RESULTS We briefly introduce the bacterial lipoprotein biosynthetic pathway and describe the structures and functions of three key enzymes in detail. In addition, we present much knowledge on ligand recognition that may facilitate structure-based drug design. Moreover, we focus on the SAR of LspA inhibitors and discuss their potency and drug-likeness. CONCLUSION This review presents a clear background of lipoprotein biosynthetic pathway and provides practical clues for structure-based drug design. In particular, the most up-to-date knowledge on the SAR of lead compounds targeting this pathway would be a good reference for discovery of a novel class of antibacterial agents.
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Affiliation(s)
- Jie Xia
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of New Drug Research and Development, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Bo Feng
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of New Drug Research and Development, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Gang Wen
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of New Drug Research and Development, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Wenjie Xue
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of New Drug Research and Development, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Guixing Ma
- Department of Biology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment and SUSTech-HKU joint laboratories for matrix biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hongmin Zhang
- Department of Biology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment and SUSTech-HKU joint laboratories for matrix biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Song Wu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of New Drug Research and Development, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
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Evidence to Suggest Bacterial Lipoprotein Diacylglyceryl Transferase (Lgt) is a Weakly Associated Inner Membrane Protein. J Membr Biol 2019; 252:563-575. [DOI: 10.1007/s00232-019-00076-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 06/14/2019] [Indexed: 10/26/2022]
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6
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Complete genome sequence of Pseudomonas frederiksbergensis ERDD5:01 revealed genetic bases for survivability at high altitude ecosystem and bioprospection potential. Genomics 2018. [PMID: 29530765 DOI: 10.1016/j.ygeno.2018.03.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pseudomonas frederiksbergensis ERDD5:01 is a psychrotrophic bacteria isolated from the glacial stream flowing from East Rathong glacier in Sikkim Himalaya. The strain showed survivability at high altitude stress conditions like freezing, frequent freeze-thaw cycles, and UV-C radiations. The complete genome of 5,746,824 bp circular chromosome and a plasmid of 371,027 bp was sequenced to understand the genetic basis of its survival strategy. Multiple copies of cold-associated genes encoding cold active chaperons, general stress response, osmotic stress, oxidative stress, membrane/cell wall alteration, carbon storage/starvation and, DNA repair mechanisms supported its survivability at extreme cold and radiations corroborating with the bacterial physiological findings. The molecular cold adaptation analysis in comparison with the genome of 15 mesophilic Pseudomonas species revealed functional insight into the strategies of cold adaptation. The genomic data also revealed the presence of industrially important enzymes.
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Stringency of bacterial prolipoprotein signal peptidase (LspA) in recognition of signal peptides - Structure-function correlation. Biochem Biophys Res Commun 2017; 488:413-417. [PMID: 28506828 DOI: 10.1016/j.bbrc.2017.05.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 05/11/2017] [Indexed: 11/22/2022]
Abstract
Bacterial lipid modification of proteins is an essential post-translational event committed by Phosphatidylglycerol: prolipoprotein diacylglyceryl transferase (Lgt) by catalysing diacyglyceryl transfer from Phosphatidylglycerol to cysteine present in the characteristic 'lipobox' ([LVI] (-3) [ASTVI] (-2) [GAS] (-1) C (+1)) of prolipoprotein signal peptides. This is then followed by the cleavage of the signal peptide by lipoprotein-specific signal peptidase (LspA). It had been known for long that threonine at the -1 position allows diacylglyceryl modification by Lgt, but not signal peptide cleavage by LspA. We have addressed this unexplained stringency by computational analysis of the recently published 3D structure of LspA with its competitive inhibitor as well as transition state analogue, globomycin using PyMoL viewing tool and VADAR (Volume, Area, Dihedral Angle Reporter) web server. The propensity to form hydrogen bond (2.9a) between the hydroxyl group of threonine (not possible with serine) and the NH of the lipid-modified cysteine, possible only in the transition state, will prevent the protonation of NH of the leaving peptide and therefore its cleavage. This knowledge could be useful for designing inhibitors of this essential pathway in bacteria or for engineering LspA.
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Identification of the Lyso-Form N-Acyl Intramolecular Transferase in Low-GC Firmicutes. J Bacteriol 2017; 199:JB.00099-17. [PMID: 28320885 DOI: 10.1128/jb.00099-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/14/2017] [Indexed: 12/25/2022] Open
Abstract
Bacterial lipoproteins are embedded in the cell membrane of both Gram-positive and Gram-negative bacteria, where they serve numerous functions central to cell envelope physiology. Lipoproteins are tethered to the membrane by an N-acyl-S-(mono/di)-acyl-glyceryl-cysteine anchor that is variously acylated depending on the genus. In several low-GC, Gram-positive firmicutes, a monoacyl-glyceryl-cysteine with an N-terminal fatty acid (known as the lyso form) has been reported, though how it is formed is unknown. Here, through an intergenic complementation rescue assay in Escherichia coli, we report the identification of a common orthologous transmembrane protein in both Enterococcus faecalis and Bacillus cereus that is capable of forming lyso-form lipoproteins. When deleted from the native host, lipoproteins remain diacylated with a free N terminus, as maturation to the N-acylated lyso form is abolished. Evidence is presented suggesting that the previously unknown gene product functions through a novel intramolecular transacylation mechanism, transferring a fatty acid from the diacylglycerol moiety to the α-amino group of the lipidated cysteine. As such, the discovered gene has been named lipoprotein intramolecular transacylase (lit), to differentiate it from the gene for the intermolecular N-acyltransferase (lnt) involved in triacyl lipoprotein biosynthesis in Gram-negative organisms.IMPORTANCE This study identifies a new enzyme, conserved among low-GC, Gram-positive bacteria, that is involved in bacterial lipoprotein biosynthesis and synthesizes lyso-form lipoproteins. Its discovery is an essential first step in determining the physiological role of N-terminal lipoprotein acylation in Gram-positive bacteria and how these modifications impact bacterial cell envelope function.
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9
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Molecular Bases Determining Daptomycin Resistance-Mediated Resensitization to β-Lactams (Seesaw Effect) in Methicillin-Resistant Staphylococcus aureus. Antimicrob Agents Chemother 2016; 61:AAC.01634-16. [PMID: 27795377 DOI: 10.1128/aac.01634-16] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/12/2016] [Indexed: 12/18/2022] Open
Abstract
Antimicrobial resistance is recognized as one of the principal threats to public health worldwide, yet the problem is increasing. Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) strains are among the most difficult to treat in clinical settings due to the resistance of MRSA to nearly all available antibiotics. The cyclic anionic lipopeptide antibiotic daptomycin (DAP) is the clinical mainstay of anti-MRSA therapy. The decreased susceptibility to DAP (DAP resistance [DAPr]) reported in MRSA is frequently accompanied by a paradoxical decrease in β-lactam resistance, a process known as the "seesaw effect." Despite the observed discordance in resistance phenotypes, the combination of DAP and β-lactams has been proven to be clinically effective for the prevention and treatment of infections due to DAPr MRSA strains. However, the mechanisms underlying the interactions between DAP and β-lactams are largely unknown. In the study described here, we studied the role of mprF with DAP-induced mutations in β-lactam sensitization and its involvement in the effective killing by the DAP-oxacillin (OXA) combination. DAP-OXA-mediated effects resulted in cell wall perturbations, including changes in peptidoglycan insertion, penicillin-binding protein 2 (PBP 2) delocalization, and reduced membrane amounts of PBP 2a, despite the increased transcription of mecA through mec regulatory elements. We have found that the VraSR sensor-regulator is a key component of DAP resistance, triggering mutated mprF-mediated cell membrane (CM) modifications that result in impairment of PrsA location and chaperone functions, both of which are essential for PBP 2a maturation, the key determinant of β-lactam resistance. These observations provide for the first time evidence that synergistic effects between DAP and β-lactams involve PrsA posttranscriptional regulation of CM-associated PBP 2a.
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10
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Dufrisne MB, Petrou VI, Clarke OB, Mancia F. Structural basis for catalysis at the membrane-water interface. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:1368-1385. [PMID: 27913292 DOI: 10.1016/j.bbalip.2016.11.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 11/27/2022]
Abstract
The membrane-water interface forms a uniquely heterogeneous and geometrically constrained environment for enzymatic catalysis. Integral membrane enzymes sample three environments - the uniformly hydrophobic interior of the membrane, the aqueous extramembrane region, and the fuzzy, amphipathic interfacial region formed by the tightly packed headgroups of the components of the lipid bilayer. Depending on the nature of the substrates and the location of the site of chemical modification, catalysis may occur in each of these environments. The availability of structural information for alpha-helical enzyme families from each of these classes, as well as several beta-barrel enzymes from the bacterial outer membrane, has allowed us to review here the different ways in which each enzyme fold has adapted to the nature of the substrates, products, and the unique environment of the membrane. Our focus here is on enzymes that process lipidic substrates. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop.
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Affiliation(s)
- Meagan Belcher Dufrisne
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA
| | - Vasileios I Petrou
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA
| | - Oliver B Clarke
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Filippo Mancia
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA.
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11
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Mao G, Zhao Y, Kang X, Li Z, Zhang Y, Wang X, Sun F, Sankaran K, Zhang XC. Crystal structure of E. coli lipoprotein diacylglyceryl transferase. Nat Commun 2016; 7:10198. [PMID: 26729647 PMCID: PMC4728403 DOI: 10.1038/ncomms10198] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 11/16/2015] [Indexed: 02/07/2023] Open
Abstract
Lipoprotein biogenesis is essential for bacterial survival. Phosphatidylglycerol:prolipoprotein diacylglyceryl transferase (Lgt) is an integral membrane enzyme that catalyses the first reaction of the three-step post-translational lipid modification. Deletion of the lgt gene is lethal to most Gram-negative bacteria. Here we present the crystal structures of Escherichia coli Lgt in complex with phosphatidylglycerol and the inhibitor palmitic acid at 1.9 and 1.6 Å resolution, respectively. The structures reveal the presence of two binding sites and support the previously reported structure–function relationships of Lgt. Complementation results of lgt-knockout cells with different mutant Lgt variants revealed critical residues, including Arg143 and Arg239, that are essential for diacylglyceryl transfer. Using a GFP-based in vitro assay, we correlated the activities of Lgt with structural observations. Together, the structural and biochemical data support a mechanism whereby substrate and product, lipid-modified lipobox-containing peptide, enter and leave the enzyme laterally relative to the lipid bilayer. Bacterial lipoproteins have important biological functions, and the lipoprotien biogenesis enzyme Lgt is essential in most gram-negative bacteria. Here, the authors use structural and biochemical techniques to shed light on the function of Lgt in post-translational transacylation modification.
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Affiliation(s)
- Guotao Mao
- National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Zhao
- National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Xusheng Kang
- National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
| | - Zhijie Li
- National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
| | - Yan Zhang
- National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
| | - Xianping Wang
- National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
| | - Fei Sun
- National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
| | | | - Xuejun C Zhang
- National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
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12
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Buddelmeijer N. The molecular mechanism of bacterial lipoprotein modification—How, when and why? FEMS Microbiol Rev 2015; 39:246-61. [DOI: 10.1093/femsre/fuu006] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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13
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Secretion of bacterial lipoproteins: through the cytoplasmic membrane, the periplasm and beyond. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:1509-16. [PMID: 24780125 DOI: 10.1016/j.bbamcr.2014.04.022] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 04/16/2014] [Accepted: 04/18/2014] [Indexed: 11/20/2022]
Abstract
Bacterial lipoproteins are peripherally anchored membrane proteins that play a variety of roles in bacterial physiology and virulence in monoderm (single membrane-enveloped, e.g., gram-positive) and diderm (double membrane-enveloped, e.g., gram-negative) bacteria. After export of prolipoproteins through the cytoplasmic membrane, which occurs predominantly but not exclusively via the general secretory or Sec pathway, the proteins are lipid-modified at the cytoplasmic membrane in a multistep process that involves sequential modification of a cysteine residue and cleavage of the signal peptide by the signal II peptidase Lsp. In both monoderms and diderms, signal peptide processing is preceded by acylation with a diacylglycerol through preprolipoprotein diacylglycerol transferase (Lgt). In diderms but also some monoderms, lipoproteins are further modified with a third acyl chain through lipoprotein N-acyl transferase (Lnt). Fully modified lipoproteins that are destined to be anchored in the inner leaflet of the outer membrane (OM) are selected, transported and inserted by the Lol (lipoprotein outer membrane localization) pathway machinery, which consists of the inner-membrane (IM) ABC transporter-like LolCDE complex, the periplasmic LolA chaperone and the OM LolB lipoprotein receptor. Retention of lipoproteins in the cytoplasmic membrane results from Lol avoidance signals that were originally described as the "+2 rule". Surface localization of lipoproteins in diderms is rare in most bacteria, with the exception of several spirochetal species. Type 2 (T2SS) and type 5 (T5SS) secretion systems are involved in secretion of specific surface lipoproteins of γ-proteobacteria. In the model spirochete Borrelia burgdorferi, surface lipoprotein secretion does not follow established sorting rules, but remains dependent on N-terminal peptide sequences. Secretion through the outer membrane requires maintenance of lipoproteins in a translocation-competent unfolded conformation, likely through interaction with a periplasmic holding chaperone, which delivers the proteins to an outer membrane lipoprotein flippase. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
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Cho K, Arimoto T, Igarashi T, Yamamoto M. Involvement of lipoprotein PpiA ofStreptococcus gordoniiin evasion of phagocytosis by macrophages. Mol Oral Microbiol 2013; 28:379-91. [DOI: 10.1111/omi.12031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2013] [Indexed: 11/29/2022]
Affiliation(s)
| | - T. Arimoto
- Department of Oral Microbiology and Immunology; Showa University School of Dentistry; Tokyo; Japan
| | - T. Igarashi
- Department of Oral Microbiology and Immunology; Showa University School of Dentistry; Tokyo; Japan
| | - M. Yamamoto
- Department of Periodontology; Showa University School of Dentistry; Tokyo; Japan
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15
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Banerjee S, Sankaran K. First ever isolation of bacterial prolipoprotein diacylglyceryl transferase in single step from Lactococcus lactis. Protein Expr Purif 2013; 87:120-8. [DOI: 10.1016/j.pep.2012.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 11/05/2012] [Accepted: 11/06/2012] [Indexed: 10/27/2022]
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16
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Nakayama H, Kurokawa K, Lee BL. Lipoproteins in bacteria: structures and biosynthetic pathways. FEBS J 2012; 279:4247-68. [PMID: 23094979 DOI: 10.1111/febs.12041] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 10/02/2012] [Accepted: 10/19/2012] [Indexed: 11/29/2022]
Abstract
Bacterial lipoproteins are characterized by the presence of a conserved N-terminal lipid-modified cysteine residue that allows the hydrophilic protein to anchor onto bacterial cell membranes. These proteins play important roles in a wide variety of bacterial physiological processes, including virulence, and induce innate immune reactions by functioning as ligands of the mammalian Toll-like receptor 2. We review recent advances in our understanding of bacterial lipoprotein structure, biosynthesis and structure-function relationships between bacterial lipoproteins and Toll-like receptor 2. Notably, 40 years after the first report of the triacyl structure of Braun's lipoprotein in Escherichia coli, recent intensive MS-based analyses have led to the discovery of three new lipidated structures of lipoproteins in monoderm bacteria: the lyso, N-acetyl and peptidyl forms. Moreover, the bacterial lipoprotein structure is considered to be constant in each bacterium; however, lipoprotein structures in Staphylococcus aureus vary between the diacyl and triacyl forms depending on the environmental conditions. Thus, the lipidation state of bacterial lipoproteins, particularly in monoderm bacteria, is more complex than previously assumed.
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Affiliation(s)
- Hiroshi Nakayama
- Biomolecular Characterization Team, RIKEN Advanced Science Institute, Wako, Saitama, Japan.
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17
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A phylum level analysis reveals lipoprotein biosynthesis to be a fundamental property of bacteria. Protein Cell 2012; 3:163-70. [PMID: 22410786 DOI: 10.1007/s13238-012-2023-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Bacterial lipoproteins are proteins that are post-translationally modified with a diacylglyceride at an N-terminal cysteine, which serves to tether these proteins to the outer face of the plasma membrane or to the outer membrane. This paper reviews recent insights into the enzymology of bacterial lipoprotein biosynthesis and localization. Moreover, we use bioinformatic analyses of bacterial lipoprotein signal peptide features and of the key biosynthetic enzymes to consider the distribution of lipoprotein biosynthesis at the phylum level. These analyses support the important conclusion that lipoprotein biosynthesis is a fundamental pathway utilized across the domain bacteria. Moreover, with the exception of a small number of sequences likely to derive from endosymbiont genomes, the enzymes of bacterial lipoprotein biosynthesis appear unique to bacteria, making this pathway an attractive target for the development of novel antimicrobials. Whilst lipoproteins with comparable signal peptide features are encoded in the genomes of Archaea, it is clear that these lipoproteins have a distinctive biosynthetic pathway that has yet to be characterized.
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18
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Functional analyses of mycobacterial lipoprotein diacylglyceryl transferase and comparative secretome analysis of a mycobacterial lgt mutant. J Bacteriol 2012; 194:3938-49. [PMID: 22609911 DOI: 10.1128/jb.00127-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Preprolipopoprotein diacylglyceryl transferase (Lgt) is the gating enzyme of lipoprotein biosynthesis, and it attaches a lipid structure to the N-terminal part of preprolipoproteins. Using Lgt from Escherichia coli in a BLASTp search, we identified the corresponding Lgt homologue in Mycobacterium tuberculosis and two homologous (MSMEG_3222 and MSMEG_5408) Lgt in Mycobacterium smegmatis. M. tuberculosis lgt was shown to be essential, but an M. smegmatis ΔMSMEG_3222 mutant could be generated. Using Triton X-114 phase separation and [(14)C]palmitic acid incorporation, we demonstrate that MSMEG_3222 is the major Lgt in M. smegmatis. Recombinant M. tuberculosis lipoproteins Mpt83 and LppX are shown to be localized in the cell envelope of parental M. smegmatis but were absent from the cell membrane and cell wall in the M. smegmatis ΔMSMEG_3222 strain. In a proteomic study, 106 proteins were identified and quantified in the secretome of wild-type M. smegmatis, including 20 lipoproteins. All lipoproteins were secreted at higher levels in the ΔMSMEG_3222 mutant. We identify the major Lgt in M. smegmatis, show that lipoproteins lacking the lipid anchor are secreted into the culture filtrate, and demonstrate that M. tuberculosis lgt is essential and thus a validated drug target.
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Toll-like receptors (TLRs) in innate immune defense against Staphylococcus aureus. Int J Artif Organs 2012; 34:799-810. [PMID: 22094559 DOI: 10.5301/ijao.5000030] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2011] [Indexed: 01/01/2023]
Abstract
Toll-like receptors (TLRs) are the most important class of innate pattern recognition receptors (PRRs) by which host immune and non-immune cells are able to recognize pathogen-associated molecular patterns (PAMPs). Most mammalian species have 10 to 15 types of TLRs. TLRs are believed to function as homo- or hetero-dimers. TLR2, which plays a crucial role in recognizing PAMPs from Staphylococcus aureus, forms heterodimers with TLR1 or TLR6 and each dimer has a different ligand specificity. Staphylococcal lipoproteins, Panton-Valentine toxin and Phenol Soluble Modulins have been identified as potent TLR2 ligands. Conversely, the ligand function attributed to peptidoglycan and LTA remains controversial. TLR2 uses a MyD88-dependent signaling pathway that results in NF-kB translocation into the nucleus and activation of the expression of pro-inflammatory cytokine genes. Recognition rouses both an inflammatory response, culminating in the phagocytosis of bacteria, and an adaptive immune response, with the presentation of resulting bacterial compounds to T cells. Here, recent advances on the recognition of S. aureus by TLRs are presented and discussed, as well as the new therapeutic opportunities deriving from this new knowledge.
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20
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Sundaram S, Banerjee S, Sankaran K. The first nonradioactive fluorescence assay for phosphatidylglycerol:prolipoprotein diacylglyceryl transferase that initiates bacterial lipoprotein biosynthesis. Anal Biochem 2012; 423:163-70. [PMID: 22342619 DOI: 10.1016/j.ab.2012.01.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 01/17/2012] [Accepted: 01/19/2012] [Indexed: 10/14/2022]
Abstract
The unique and physiologically vital bacterial enzyme, prolipoprotein diacylglyceryl transferase (Lgt), which catalyzes the committed first step in the posttranslational transfer of diacylglyceryl group from phosphatidylglycerol to the prospective N-terminal cysteine of prolipoproteins, remains to be characterized for want of a simpler but equally sensitive nonradioactive assay. We, for the first time, report a coupled enzymatic fluorescence assay for Lgt using the de novo synthetic peptide substrate MKATKSAVGSTLAGCSSHHHHHH. The assay is based on the conversion of the by-product, glycerol-1-phosphate, to dihydroxyacetone using an alkaline phosphatase-glycerol dehydrogenase combination and estimating the fluorescence of the coupled reduction of resazurin to resorufin. The minimum amount of glycerol-1-phosphate, and hence the modified peptide, detected by this method is approximately 20pmol, thereby making this assay a promising alternative to the radioactive assays. The assay is rapid, more convenient, less laborious, and suitable for purification and characterization of Lgt.
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21
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Phosphatidylglycerol::prolipoprotein diacylglyceryl transferase (Lgt) of Escherichia coli has seven transmembrane segments, and its essential residues are embedded in the membrane. J Bacteriol 2012; 194:2142-51. [PMID: 22287519 DOI: 10.1128/jb.06641-11] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Lgt of Escherichia coli catalyzes the transfer of an sn-1,2-diacylglyceryl group from phosphatidylglycerol to prolipoproteins. The enzyme is essential for growth, as demonstrated here by the analysis of an lgt depletion strain. Cell fractionation demonstrated that Lgt is an inner membrane protein. Its membrane topology was determined by fusing Lgt to β-galactosidase and alkaline phosphatase and by substituted cysteine accessibility method (SCAM) studies. The data show that Lgt is embedded in the membrane by seven transmembrane segments, that its N terminus faces the periplasm, and that its C terminus faces the cytoplasm. Highly conserved amino acids in Lgt of both Gram-negative and Gram-positive bacteria were identified. Lgt enzymes are characterized by a so-called Lgt signature motif in which four residues are invariant. Ten conserved residues were replaced with alanine, and the activity of these Lgt variants was analyzed by their ability to complement the lgt depletion strain. Residues Y26, N146, and G154 are absolutely required for Lgt function, and R143, E151, R239, and E243 are important. The results demonstrate that the majority of the essential residues of Lgt are located in the membrane and that the Lgt signature motif faces the periplasm.
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22
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Surface lipoprotein PpiA of Streptococcus mutans suppresses scavenger receptor MARCO-dependent phagocytosis by macrophages. Infect Immun 2011; 79:4933-40. [PMID: 21986627 DOI: 10.1128/iai.05693-11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Streptococcus mutans is associated with the initiation and progression of human dental caries and is occasionally isolated from the blood of patients with bacteremia and infective endocarditis. For the pathogen to survive in the infected host, surface lipoproteins of S. mutans are likely to play important roles in interactions with the innate immune system. To clarify the role that a putative lipoprotein, peptidyl-prolyl cis/trans-isomerase (PpiA), of S. mutans plays in the macrophage response, we investigated the response of THP-1-derived macrophages to S. mutans challenge. The deletion of the gene encoding Lgt eliminated PpiA on the cell surface of S. mutans, which implies that PpiA is a lipoprotein that is lipid anchored in the cell membrane by Lgt. Human and murine peritoneal macrophages both showed higher phagocytic activities for the ppiA and lgt mutants than the wild type, which indicates that the presence of PpiA reduces S. mutans phagocytosis. In addition, infection with S. mutans markedly induced mRNAs of macrophage receptor with collagenous structure (MARCO) and scavenger receptor A (SR-A) in human macrophages. In particular, transcriptional and translational levels of MARCO in human macrophages infected with the ppiA mutant were higher than those in macrophages infected with the wild type. Phagocytosis of S. mutans by human macrophages markedly decreased after treatment with anti-MARCO IgG. These results demonstrate that the S. mutans lipoprotein PpiA contributes to suppression of MARCO-mediated phagocytosis of this bacterium by macrophages.
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23
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Abstract
Bacterial lipoproteins are a set of membrane proteins with many different functions. Due to this broad-ranging functionality, these proteins have a considerable significance in many phenomena, from cellular physiology through cell division and virulence. Here we give a general overview of lipoprotein biogenesis and highlight examples of the roles of lipoproteins in bacterial disease caused by a selection of medically relevant Gram-negative and Gram-positive pathogens: Mycobacterium tuberculosis, Streptococcus pneumoniae, Borrelia burgdorferi, and Neisseria meningitidis. Lipoproteins have been shown to play key roles in adhesion to host cells, modulation of inflammatory processes, and translocation of virulence factors into host cells. As such, a number of lipoproteins have been shown to be potential vaccines. This review provides a summary of some of the reported roles of lipoproteins and of how this knowledge has been exploited in some cases for the generation of novel countermeasures to bacterial diseases.
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24
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Vickerman MM, Flannagan SE, Jesionowski AM, Brossard KA, Clewell DB, Sedgley CM. A genetic determinant in Streptococcus gordonii Challis encodes a peptide with activity similar to that of enterococcal sex pheromone cAM373, which facilitates intergeneric DNA transfer. J Bacteriol 2010; 192:2535-45. [PMID: 20233933 PMCID: PMC2863574 DOI: 10.1128/jb.01689-09] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Accepted: 03/03/2010] [Indexed: 11/20/2022] Open
Abstract
Enterococcus faecalis strains secrete multiple peptides representing different sex pheromones that induce mating responses by bacteria carrying specific conjugative plasmids. The pheromone cAM373, which induces a response by the enterococcal plasmid pAM373, has been of interest because a similar activity is also secreted by Streptococcus gordonii and Staphylococcus aureus. The potential to facilitate intergeneric DNA transfer from E. faecalis is of concern because of extensive multiple antibiotic resistance, including vancomycin resistance, that has emerged among enterococci in recent years. Here, we characterize the related pheromone determinant in S. gordonii and show that the peptide it encodes, gordonii-cAM373, does indeed induce transfer of plasmid DNA from E. faecalis into S. gordonii. The streptococcal determinant camG encodes a lipoprotein with a leader sequence, the last 7 residues of which represent the gordonii-cAM373 heptapeptide SVFILAA. Synthetic forms of the peptide had activity similar to that of the enterococcal cAM373 AIFILAS. The lipoprotein moiety bore no resemblance to the lipoprotein encoded by E. faecalis. We also identified determinants in S. gordonii encoding a signal peptidase and an Eep-like zinc metalloprotease (lspA and eep, respectively) similar to those involved in processing certain pheromone precursors in E. faecalis. Mutations generated in camG, lspA, and eep each resulted in the ablation of gordonii-cAM373 activity in culture supernatants. This is the first genetic analysis of a potential sex pheromone system in a commensal oral streptococcal species, which may have implications for intergeneric gene acquisition in oral biofilms.
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Affiliation(s)
- M. M. Vickerman
- Department of Periodontics and Endodontics and Department of Oral Biology, School of Dental Medicine, University at Buffalo, 223 Foster Hall, Buffalo, New York 14214, Cariology, Restorative Sciences and Endodontics, School of Dentistry, Biologic and Materials Sciences, School of Dentistry, and Department of Microbiology and Immunology, Medical School, The University of Michigan, 1011 North University, Ann Arbor, Michigan 48109
| | - S. E. Flannagan
- Department of Periodontics and Endodontics and Department of Oral Biology, School of Dental Medicine, University at Buffalo, 223 Foster Hall, Buffalo, New York 14214, Cariology, Restorative Sciences and Endodontics, School of Dentistry, Biologic and Materials Sciences, School of Dentistry, and Department of Microbiology and Immunology, Medical School, The University of Michigan, 1011 North University, Ann Arbor, Michigan 48109
| | - A. M. Jesionowski
- Department of Periodontics and Endodontics and Department of Oral Biology, School of Dental Medicine, University at Buffalo, 223 Foster Hall, Buffalo, New York 14214, Cariology, Restorative Sciences and Endodontics, School of Dentistry, Biologic and Materials Sciences, School of Dentistry, and Department of Microbiology and Immunology, Medical School, The University of Michigan, 1011 North University, Ann Arbor, Michigan 48109
| | - K. A. Brossard
- Department of Periodontics and Endodontics and Department of Oral Biology, School of Dental Medicine, University at Buffalo, 223 Foster Hall, Buffalo, New York 14214, Cariology, Restorative Sciences and Endodontics, School of Dentistry, Biologic and Materials Sciences, School of Dentistry, and Department of Microbiology and Immunology, Medical School, The University of Michigan, 1011 North University, Ann Arbor, Michigan 48109
| | - D. B. Clewell
- Department of Periodontics and Endodontics and Department of Oral Biology, School of Dental Medicine, University at Buffalo, 223 Foster Hall, Buffalo, New York 14214, Cariology, Restorative Sciences and Endodontics, School of Dentistry, Biologic and Materials Sciences, School of Dentistry, and Department of Microbiology and Immunology, Medical School, The University of Michigan, 1011 North University, Ann Arbor, Michigan 48109
| | - C. M. Sedgley
- Department of Periodontics and Endodontics and Department of Oral Biology, School of Dental Medicine, University at Buffalo, 223 Foster Hall, Buffalo, New York 14214, Cariology, Restorative Sciences and Endodontics, School of Dentistry, Biologic and Materials Sciences, School of Dentistry, and Department of Microbiology and Immunology, Medical School, The University of Michigan, 1011 North University, Ann Arbor, Michigan 48109
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25
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Fujimoto Y, Hashimoto M, Furuyashiki M, Katsumoto M, Seya T, Suda Y, Fukase K. Lipopeptides from Staphylococcus aureus as Tlr2 Ligands: prediction with mrna expression, chemical synthesis, and immunostimulatory activities. Chembiochem 2010; 10:2311-5. [PMID: 19681087 DOI: 10.1002/cbic.200900242] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yukari Fujimoto
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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26
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Schmaler M, Jann NJ, Ferracin F, Landolt LZ, Biswas L, Götz F, Landmann R. Lipoproteins in Staphylococcus aureus mediate inflammation by TLR2 and iron-dependent growth in vivo. THE JOURNAL OF IMMUNOLOGY 2009; 182:7110-8. [PMID: 19454708 DOI: 10.4049/jimmunol.0804292] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Lipoproteins (Lpp) are ligands of TLR2 and signal by the adaptor MyD88. As part of the bacterial cell envelope, Lpp are mainly involved in nutrient acquisition for Staphylococcus aureus. The impact of Lpp on TLR2-MyD88 activation for S. aureus in systemic infection is unknown. S. aureus strain SA113 deficient in the enzyme encoded by the prolipoprotein diacylglyceryl transferase gene (Deltalgt), which attaches the lipid anchor to pro-Lpp, was used to study benefits and costs of Lpp maturation. Lpp in S. aureus induced early and strong cytokines by TLR2-MyD88 signaling in murine peritoneal macrophages. Lpp contributed via TLR2 to pathogenesis of sepsis in C57BL/6 mice with IL-1beta, chemokine-mediated inflammation, and high bacterial numbers. In the absence of MyD88-mediated inflammation, Lpp allowed bacterial clearing from liver devoid of infiltrating cells, but still conferred a strong growth advantage in mice, which was shown to rely on iron uptake and storage in vitro and in vivo. With iron-restricted bacteria, the Lpp-related growth advantage was evident in infection of MyD88(-/-), but not of C57BL/6, mice. On the other hand, iron overload of the host restored the growth deficit of Deltalgt in MyD88(-/-), but not in immunocompetent C57BL/6 mice. These results indicate that iron acquisition is improved by Lpp of S. aureus but is counteracted by inflammation. Thus, lipid anchoring is an evolutionary advantage for S. aureus to retain essential proteins for better survival in infection.
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Affiliation(s)
- Mathias Schmaler
- Department of Biomedicine, Division Infection Biology, University Hospital Basel, Basel, Switzerland
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27
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Watanabe K, Tsuchida Y, Okibe N, Teramoto H, Suzuki N, Inui M, Yukawa H. Scanning the Corynebacterium glutamicum R genome for high-efficiency secretion signal sequences. MICROBIOLOGY-SGM 2009; 155:741-750. [PMID: 19246745 DOI: 10.1099/mic.0.024075-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Systematic screening of secretion proteins using an approach based on the completely sequenced genome of Corynebacterium glutamicum R revealed 405 candidate signal peptides, 108 of which were able to heterologously secrete an active-form alpha-amylase derived from Geobacillus stearothermophilus. These comprised 90 general secretory (Sec)-type, 10 twin-arginine translocator (Tat)-type and eight Sec-type with presumptive lipobox peptides. Only Sec- and Tat-type signals directed high-efficiency secretion. In two assays, 11 of these signals resulted in 50- to 150-fold increased amounts of secreted alpha-amylase compared with the well-known corynebacterial secretory protein PS2. While the presence of an AXA motif at the cleavage sites was readily apparent, it was the presence of a glutamine residue adjacent to the cleavage site that may affect secretion efficiency.
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Affiliation(s)
- Keiro Watanabe
- Molecular Microbiology and Biotechnology Group, Research Institute of Innovative Technology for the Earth (RITE), 9-2, Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Yoshiki Tsuchida
- Honda R&D Co., Ltd, 1-4-1 Chuo Wako, Saitama 351-0193, Japan.,Molecular Microbiology and Biotechnology Group, Research Institute of Innovative Technology for the Earth (RITE), 9-2, Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Naoko Okibe
- Molecular Microbiology and Biotechnology Group, Research Institute of Innovative Technology for the Earth (RITE), 9-2, Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Haruhiko Teramoto
- Molecular Microbiology and Biotechnology Group, Research Institute of Innovative Technology for the Earth (RITE), 9-2, Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Nobuaki Suzuki
- Molecular Microbiology and Biotechnology Group, Research Institute of Innovative Technology for the Earth (RITE), 9-2, Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Masayuki Inui
- Molecular Microbiology and Biotechnology Group, Research Institute of Innovative Technology for the Earth (RITE), 9-2, Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Hideaki Yukawa
- Molecular Microbiology and Biotechnology Group, Research Institute of Innovative Technology for the Earth (RITE), 9-2, Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
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28
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Denham EL, Ward PN, Leigh JA. In the absence of Lgt, lipoproteins are shed from Streptococcus uberis independently of Lsp. Microbiology (Reading) 2009; 155:134-141. [DOI: 10.1099/mic.0.022061-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The role of lipoprotein diacylglyceryl transferase (Lgt) and lipoprotein signal peptidase (Lsp) responsible for processing lipoproteins was investigated in Streptococcus uberis, a common cause of bovine mastitis. In the absence of Lgt, three lipoproteins [MtuA (SUB0473), Hap (SUB1625) and an extracellular solute-binding protein (SUB0365)] were detected in extracellular locations. All were shown by Edman degradation analysis to be cleaved on the carboxy side of the LXXC lipobox. Detection of MtuA, a lipoprotein shown previously to be essential for infectivity and virulence, was used as a surrogate lipoprotein marker to locate and assess processing of lipoproteins. The absence of Lgt did not prevent location of MtuA to the cell membrane, its location in the wild-type strain but, in contrast to the situation with wild-type, did result in a widespread location of this protein. In the absence of both Lgt and Lsp, MtuA was similarly released from the bacterial cell. In such strains, however, the cell-associated MtuA represented the full-length gene product, indicating that Lsp was able to cleave non-lipidated (lipo)proteins but was not responsible for their release from this bacterium.
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Affiliation(s)
- E. L. Denham
- Institute for Animal Health, Compton, Berkshire RG20 7NN, UK
| | - P. N. Ward
- Nuffield Department of Clinical Laboratory Sciences, Oxford University, John Radcliffe Hospital, Headington, Oxfordshire OX3 9DU, UK
| | - J. A. Leigh
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire LE12 5RD, UK
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29
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Arimoto T, Igarashi T. Role of prolipoprotein diacylglyceryl transferase (Lgt) and lipoprotein-specific signal peptidase II (LspA) in localization and physiological function of lipoprotein MsmE inStreptococcus mutans. ACTA ACUST UNITED AC 2008; 23:515-9. [DOI: 10.1111/j.1399-302x.2008.00455.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Selvan AT, Sankaran K. Localization and characterization of prolipoprotein diacylglyceryl transferase (Lgt) critical in bacterial lipoprotein biosynthesis. Biochimie 2008; 90:1647-55. [DOI: 10.1016/j.biochi.2008.06.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Accepted: 06/09/2008] [Indexed: 10/21/2022]
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31
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Henneke P, Dramsi S, Mancuso G, Chraibi K, Pellegrini E, Theilacker C, Hübner J, Santos-Sierra S, Teti G, Golenbock DT, Poyart C, Trieu-Cuot P. Lipoproteins are critical TLR2 activating toxins in group B streptococcal sepsis. THE JOURNAL OF IMMUNOLOGY 2008; 180:6149-58. [PMID: 18424736 DOI: 10.4049/jimmunol.180.9.6149] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Group B streptococcus (GBS) is the most important cause of neonatal sepsis, which is mediated in part by TLR2. However, GBS components that potently induce cytokines via TLR2 are largely unknown. We found that GBS strains of the same serotype differ in released factors that activate TLR2. Several lines of genetic and biochemical evidence indicated that lipoteichoic acid (LTA), the most widely studied TLR2 agonist in Gram-positive bacteria, was not essential for TLR2 activation. We thus examined the role of GBS lipoproteins in this process by inactivating two genes essential for bacterial lipoprotein (BLP) maturation: the prolipoprotein diacylglyceryl transferase gene (lgt) and the lipoprotein signal peptidase gene (lsp). We found that Lgt modification of the N-terminal sequence called lipobox was not critical for Lsp cleavage of BLPs. In the absence of lgt and lsp, lipoprotein signal peptides were processed by the type I signal peptidase. Importantly, both the Deltalgt and the Deltalsp mutant were impaired in TLR2 activation. In contrast to released factors, fixed Deltalgt and Deltalsp GBS cells exhibited normal inflammatory activity indicating that extracellular toxins and cell wall components activate phagocytes through independent pathways. In addition, the Deltalgt mutant exhibited increased lethality in a model of neonatal GBS sepsis. Notably, LTA comprised little, if any, inflammatory potency when extracted from Deltalgt GBS. In conclusion, mature BLPs, and not LTA, are the major TLR2 activating factors from GBS and significantly contribute to GBS sepsis.
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Affiliation(s)
- Philipp Henneke
- Center for Pediatrics and Adolescent Medicine, University Medical Centre Freiburg, Mathildenstrasse 1, Freiburg, Germany.
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32
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Hamilton A, Robinson C, Sutcliffe IC, Slater J, Maskell DJ, Davis-Poynter N, Smith K, Waller A, Harrington DJ. Mutation of the maturase lipoprotein attenuates the virulence of Streptococcus equi to a greater extent than does loss of general lipoprotein lipidation. Infect Immun 2006; 74:6907-19. [PMID: 17015455 PMCID: PMC1698103 DOI: 10.1128/iai.01116-06] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus equi is the causative agent of strangles, a prevalent and highly contagious disease of horses. Despite the animal suffering and economic burden associated with strangles, little is known about the molecular basis of S. equi virulence. Here we have investigated the contributions of a specific lipoprotein and the general lipoprotein processing pathway to the abilities of S. equi to colonize equine epithelial tissues in vitro and to cause disease in both a mouse model and the natural host in vivo. Colonization of air interface organ cultures after they were inoculated with a mutant strain deficient in the maturase lipoprotein (DeltaprtM(138-213), with a deletion of nucleotides 138 to 213) was significantly less than that for cultures infected with wild-type S. equi strain 4047 or a mutant strain that was unable to lipidate preprolipoproteins (Deltalgt(190-685)). Moreover, mucus production was significantly greater in both wild-type-infected and Deltalgt(190-685)-infected organ cultures. Both mutants were significantly attenuated compared with the wild-type strain in a mouse model of strangles, although 2 of 30 mice infected with the Deltalgt(190-685) mutant did still exhibit signs of disease. In contrast, only the DeltaprtM(138-213) mutant was significantly attenuated in a pony infection study, with 0 of 5 infected ponies exhibiting pathological signs of strangles compared with 4 of 4 infected with the wild-type and 3 of 5 infected with the Deltalgt(190-685) mutant. We believe that this is the first study to evaluate the contribution of lipoproteins to the virulence of a gram-positive pathogen in its natural host. These data suggest that the PrtM lipoprotein is a potential vaccine candidate, and further investigation of its activity and its substrate(s) are warranted.
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Affiliation(s)
- Andrea Hamilton
- University of Sunderland, Tyne and Wear SR1 3SD, United Kingdom
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Taylor PD, Toseland CP, Attwood TK, Flower DR. LIPPRED: A web server for accurate prediction of lipoprotein signal sequences and cleavage sites. Bioinformation 2006; 1:176-9. [PMID: 17597883 PMCID: PMC1891677 DOI: 10.6026/97320630001176] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Revised: 07/18/2006] [Accepted: 07/18/2006] [Indexed: 11/23/2022] Open
Abstract
Bacterial lipoproteins have many important functions and represent a class of possible vaccine candidates. The prediction of lipoproteins from sequence is thus an important task for computational vaccinology. Naïve-Bayesian networks were trained to identify SpaseII cleavage sites and their preceding signal sequences using a set of 199 distinct lipoprotein sequences. A comprehensive range of sequence models was used to identify the best model for lipoprotein signal sequences. The best performing sequence model was found to be 10-residues in length, including the conserved cysteine lipid attachment site and the nine residues prior to it. The sensitivity of prediction for LipPred was 0.979, while the specificity was 0.742. Here, we describe LipPred, a web server for lipoprotein prediction; available at the URL: http://www.jenner.ac.uk/LipPred/. LipPred is the most accurate method available for the detection of SpaseIIcleaved lipoprotein signal sequences and the prediction of their cleavage sites.
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Affiliation(s)
- Paul D Taylor
- The Jenner Institute, University of Oxford, Compton,Newbury, Berkshire, RG20 7NN, UK
| | | | - Teresa K Attwood
- Faculty of Life Sciences & School of Computer Science, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Darren R Flower
- The Jenner Institute, University of Oxford, Compton,Newbury, Berkshire, RG20 7NN, UK
- The Jenner Institute, University of Oxford, Compton,Newbury, Berkshire, RG20 7NN, UK
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Kim K, Oh J, Han D, Kim EE, Lee B, Kim Y. Crystal structure of PilF: functional implication in the type 4 pilus biogenesis in Pseudomonas aeruginosa. Biochem Biophys Res Commun 2005; 340:1028-38. [PMID: 16403447 DOI: 10.1016/j.bbrc.2005.12.108] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Accepted: 12/15/2005] [Indexed: 11/23/2022]
Abstract
PilF is a requisite protein involved in the type 4 pilus biogenesis system from the Gram-negative human pathogenic bacteria, Pseudomonas aeruginosa. We determined the PilF structure at a 2.2A resolution; this includes six tandem tetratrico peptide repeat (TPR) units forming right-handed superhelix. PilF structure was similar to the heat shock protein organizing protein, which interacts with the C-terminal peptide of Hsp90 and Hsp70 via a concave Asn ladder in the inner groove of TPR superhelix. After simulated screening, the C-terminal pentapeptides of PilG, PilU, PilY, and PilZ proved to be a likely candidate binding to PilF, which are ones of 25 necessary components involved in the type 4 pilus biogenesis system. We proposed that PilF would be critical as a bridgehead in protein-protein interaction and thereby, PilF may bind a necessary molecule in type 4 pilus biogenesis system such as PilG, PilU, PilY, and PilZ.
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Affiliation(s)
- Kyunggon Kim
- Division of Molecular Genomic Medicine, College of Medicine, Seoul National University, Yongon-Dong, Seoul 110-799, Republic of Korea
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Gupta RS. Protein signatures distinctive of alpha proteobacteria and its subgroups and a model for alpha-proteobacterial evolution. Crit Rev Microbiol 2005; 31:101-35. [PMID: 15986834 DOI: 10.1080/10408410590922393] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Alpha (alpha) proteobacteria comprise a large and metabolically diverse group. No biochemical or molecular feature is presently known that can distinguish these bacteria from other groups. The evolutionary relationships among this group, which includes numerous pathogens and agriculturally important microbes, are also not understood. Shared conserved inserts and deletions (i.e., indels or signatures) in molecular sequences provide a powerful means for identification of different groups in clear terms, and for evolutionary studies (see www.bacterialphylogeny.com). This review describes, for the first time, a large number of conserved indels in broadly distributed proteins that are distinctive and unifying characteristics of either all alpha-proteobacteria, or many of its constituent subgroups (i.e., orders, families, etc.). These signatures were identified by systematic analyses of proteins found in the Rickettsia prowazekii (RP) genome. Conserved indels that are unique to alpha-proteobacteria are present in the following proteins: Cytochrome c oxidase assembly protein Ctag, PurC, DnaB, ATP synthase alpha-subunit, exonuclease VII, prolipoprotein phosphatidylglycerol transferase, RP-400, FtsK, puruvate phosphate dikinase, cytochrome b, MutY, and homoserine dehydrogenase. The signatures in succinyl-CoA synthetase, cytochrome oxidase I, alanyl-tRNA synthetase, and MutS proteins are found in all alpha-proteobacteria, except the Rickettsiales, indicating that this group has diverged prior to the introduction of these signatures. A number of proteins contain conserved indels that are specific for Rickettsiales (XerD integrase and leucine aminopeptidase), Rickettsiaceae (Mfd, ribosomal protein L19, FtsZ, Sigma 70 and exonuclease VII), or Anaplasmataceae (Tgt and RP-314), and they distinguish these groups from all others. Signatures in DnaA, RP-057, and DNA ligase A are commonly shared by various Rhizobiales, Rhodobacterales, and Caulobacter, suggesting that these groups shared a common ancestor exclusive of other alpha-proteobacteria. A specific relationship between Rhodobacterales and Caulobacter is indicated by a large insert in the Asn-Gln amidotransferase. The Rhizobiales group of species are distinguished from others by a large insert in the Trp-tRNA synthetase. Signature sequences in a number of other proteins (viz. oxoglutarate dehydogenase, succinyl-CoA synthase, LytB, DNA gyrase A, LepA, and Ser-tRNA synthetase) serve to distinguish the Rhizobiaceae, Brucellaceae, and Phyllobacteriaceae families from Bradyrhizobiaceae and Methylobacteriaceae. Based on the distribution patterns of these signatures, it is now possible to logically deduce a model for the branching order among alpha-proteobacteria, which is as follows: Rickettsiales --> Rhodospirillales-Sphingomonadales --> Rhodobacterales-Caulobacterales --> Rhizobiales (Rhizobiaceaea-Brucellaceae-Phyllobacteriaceae, and Bradyrhizobiaceae). The deduced branching order is also consistent with the topologies in the 16 rRNA and other phylogenetic trees. Signature sequences in a number of other proteins provide evidence that alpha-proteobacteria is a late branching taxa within Bacteria, which branched after the delta,epsilon-subdivisions but prior to the beta,gamma-proteobacteria. The shared presence of many of these signatures in the mitochondrial (eukaryotic) homologs also provides evidence of the alpha-proteobacterial ancestry of mitochondria.
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Affiliation(s)
- Radhey S Gupta
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
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36
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Stoll H, Dengjel J, Nerz C, Götz F. Staphylococcus aureus deficient in lipidation of prelipoproteins is attenuated in growth and immune activation. Infect Immun 2005; 73:2411-23. [PMID: 15784587 PMCID: PMC1087423 DOI: 10.1128/iai.73.4.2411-2423.2005] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A lipoprotein diacylglyceryl transferase (lgt) deletion mutant of Staphylococcus aureus SA113 was constructed. The lipoprotein and prelipoprotein expression, the growth behavior, and the ability of the mutant to elicit an immune response in various host cells were studied. In the wild type, the majority of [14C]palmitate-labeled lipoproteins were located in the membrane fraction, although some lipoproteins were also present on the cell surface and in the culture supernatant. The lgt mutant completely lacked palmitate-labeled lipoproteins and released high amounts of some unmodified prelipoproteins, e.g., the oligopeptide-binding protein OppA, the peptidyl-prolyl cis-trans isomerase PrsA, and the staphylococcal iron transporter SitC, into the culture supernatant. The growth of the lgt mutant was hardly affected in rich medium but was retarded under nutrient limitation. The lgt mutant and its crude lysate induced much fewer proinflammatory cytokines and chemokines in human monocytic (MonoMac6), epithelial (pulmonary A549), and endothelial (human umbilical vein endothelial) cells than the wild type. However, in whole blood samples, the culture supernatant of the lgt mutant was equal or even superior to the wild-type supernatant in tumor necrosis factor alpha induction. Lipoprotein fractionation experiments provided evidence that a small proportion of the mature lipoproteins are released by the S. aureus wild type despite the lipid anchor and are trapped in part by the cell wall, thereby exposing the immune-activating lipid structure on the cell surface. Bacterial lipoproteins appear to be essential for a complete immune stimulation by gram-positive bacteria.
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Affiliation(s)
- Hartmut Stoll
- Mikrobielle Genetik, Universität Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany
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37
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Rediers H, Bonnecarrère V, Rainey PB, Hamonts K, Vanderleyden J, De Mot R. Development and application of a dapB-based in vivo expression technology system to study colonization of rice by the endophytic nitrogen-fixing bacterium Pseudomonas stutzeri A15. Appl Environ Microbiol 2004; 69:6864-74. [PMID: 14602651 PMCID: PMC262291 DOI: 10.1128/aem.69.11.6864-6874.2003] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas stutzeri A15 is a nitrogen-fixing bacterium isolated from paddy rice. Strain A15 is able to colonize and infect rice roots. This strain may provide rice plants with fixed nitrogen and hence promote plant growth. In this article, we describe the use of dapB-based in vivo expression technology to identify P. stutzeri A15 genes that are specifically induced during colonization and infection (cii). We focused on the identification of P. stutzeri A15 genes that are switched on during rice root colonization and are switched off during free-living growth on synthetic medium. Several transcriptional fusions induced in the rice rhizosphere were isolated. Some of the corresponding genes are involved in the stress response, chemotaxis, metabolism, and global regulation, while others encode putative proteins with unknown functions or without significant homology to known proteins.
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Affiliation(s)
- Hans Rediers
- Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, B-3001 Heverlee, Belgium
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38
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Asanuma N, Hino T. Molecular characterization of HPr and related enzymes, and regulation of HPr phosphorylation in the ruminal bacterium Streptococcus bovis. Arch Microbiol 2003; 179:205-13. [PMID: 12610726 DOI: 10.1007/s00203-003-0516-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2002] [Revised: 12/20/2002] [Accepted: 12/20/2002] [Indexed: 10/20/2022]
Abstract
Molecular properties of HPr, enzyme I, and HPr kinase in Streptococcus bovis, and the regulation of HPr phosphorylation were examined. The genes encoding HPr (ptsH) and enzyme I (ptsI) were found to be cotranscribed. Two transcriptional start sites were detected in a region upstream of the HPr kinase gene (hprK). HPr kinase had both HPr-phosphorylating and HPr-dephosphorylating activities. The importance of phosphorylation of Ser-46 in HPr was shown by using a mutant HPr in which Ser-46 was replaced by Ala. When S. bovis was grown in glucose-limited medium, the amount of seryl-phosphorylated HPr (HPr-[Ser-P]) decreased drastically as the growth rate decreased. In contrast, the amount of histidyl-phosphorylated HPr (HPr-[His-P]) increased gradually as the growth rate decreased. The amount of HPr kinase did not greatly change with the growth phase, whereas the intracellular P(i) concentration increased as the growth rate decreased. HPr-[Ser-P] decreased as the intracellular P(i) increased as a consequence of inhibition of HPr kinase activity by P(i) and simultaneous enhancement of HPr-[Ser-P] phosphatase activity by P(i). Thus, it is conceivable that the ratio of HPr-[Ser-P] to HPr-[His-P] is regulated by the bifunctional activity of HPr kinase in response to intracellular P(i) concentration.
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Affiliation(s)
- Narito Asanuma
- Department of Life Science, College of Agriculture, Meiji University, Higashimita, Tama-ku, 214-8571 Kawasaki, Japan
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39
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Sutcliffe IC, Harrington DJ. Pattern searches for the identification of putative lipoprotein genes in Gram-positive bacterial genomes. MICROBIOLOGY (READING, ENGLAND) 2002; 148:2065-2077. [PMID: 12101295 DOI: 10.1099/00221287-148-7-2065] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
N-terminal lipidation is a major mechanism by which bacteria can tether proteins to membranes and one which is of particular importance to Gram-positive bacteria due to the absence of a retentive outer membrane. Lipidation is directed by the presence of a cysteine-containing 'lipobox' within the lipoprotein signal peptide sequence and this feature has greatly facilitated the identification of putative lipoproteins by gene sequence analysis. The properties of lipoprotein signal peptides have been described previously by the Prosite pattern PS00013. Here, a dataset of 33 experimentally verified Gram-positive bacterial lipoproteins (excluding those from Mollicutes) has been identified by an extensive literature review. The signal peptide features of these lipoproteins have been analysed to create a refined pattern, G+LPP, which is more specific for the identification of Gram-positive bacterial lipoproteins. The ability of this pattern to identify probable lipoprotein sequences is demonstrated by a search of the genome of Streptococcus pyogenes, in comparison with sequences identified using PS00013. Greater discrimination against likely false-positives was evident from the use of G+LPP compared with PS00013. These data confirm the likely abundance of lipoproteins in Gram-positive bacterial genomes, with at least 25 probable lipoproteins identified in S. pyogenes
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Affiliation(s)
- Iain C Sutcliffe
- Fleming Building, Institute of Pharmacy, Chemistry and Biomedical Sciences, University of Sunderland, Sunderland SR2 3SD, UK1
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40
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Capitani G, Rossmann R, Sargent DF, Grütter MG, Richmond TJ, Hennecke H. Structure of the soluble domain of a membrane-anchored thioredoxin-like protein from Bradyrhizobium japonicum reveals unusual properties. J Mol Biol 2001; 311:1037-48. [PMID: 11531338 DOI: 10.1006/jmbi.2001.4913] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
TlpA is an unusual thioredoxin-like protein present in the nitrogen-fixing soil bacterium Bradyrhizobium japonicum. A hydrophobic N-terminal transmembrane domain anchors it to the cytoplasmic membrane, whereby the hydrophilic thioredoxin domain becomes exposed to the periplasmic space. There, TlpA catalyses an essential reaction, probably a reduction, in the biogenesis of cytochrome aa(3). The soluble thioredoxin domain (TlpA(sol)), devoid of the membrane anchor, was purified and crystallized. Oxidized TlpA(sol) crystallized as a non-covalent dimer in the space group P2(1)2(1)2(1). The X-ray structure analysis was carried out by isomorphous replacement using a xenon derivative. This resulted in a high-resolution (1.6 A) three-dimensional structure that displayed all of the features of a classical thioredoxin fold. A number of peculiar structural details were uncovered: (i) Only one of the two active-site-cysteine sulphurs (Cys72, the one closer to the N terminus) is exposed on the surface, making it the likely nucleophile for the reduction of target proteins. (ii) TlpA(sol) possesses a unique structural disulphide bond, formed between Cys10 and Cys155, which connects an unprecedented N-terminal alpha helix with a beta sheet near the C terminus. (iii) An insertion of about 25 amino acid residues, not found in the thioredoxin prototype of Escherichia coli, contributes only marginally to the thioredoxin fold, but forms an extra, surface-exposed alpha helix. This region plus another surface-exposed stretch (-Ile-Gly-Arg-Ala-), which is absent even in the closest TlpA relatives, might be considered as specificity determinants for the recognition of target proteins in the periplasm. The TlpA(sol) structure paves the way towards unraveling important structure-function relationships by rational mutagenesis.
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Affiliation(s)
- G Capitani
- Biochemisches Institut, Universität Zürich, CH-8057 Zürich, Switzerland
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41
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Dossonnet V, Monedero V, Zagorec M, Galinier A, Pérez-Martínez G, Deutscher J. Phosphorylation of HPr by the bifunctional HPr Kinase/P-ser-HPr phosphatase from Lactobacillus casei controls catabolite repression and inducer exclusion but not inducer expulsion. J Bacteriol 2000; 182:2582-90. [PMID: 10762262 PMCID: PMC111324 DOI: 10.1128/jb.182.9.2582-2590.2000] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/1999] [Accepted: 02/09/2000] [Indexed: 11/20/2022] Open
Abstract
We have cloned and sequenced the Lactobacillus casei hprK gene encoding the bifunctional enzyme HPr kinase/P-Ser-HPr phosphatase (HprK/P). Purified recombinant L. casei HprK/P catalyzes the ATP-dependent phosphorylation of HPr, a phosphocarrier protein of the phosphoenolpyruvate:carbohydrate phosphotransferase system at the regulatory Ser-46 as well as the dephosphorylation of seryl-phosphorylated HPr (P-Ser-HPr). The two opposing activities of HprK/P were regulated by fructose-1,6-bisphosphate, which stimulated HPr phosphorylation, and by inorganic phosphate, which stimulated the P-Ser-HPr phosphatase activity. A mutant producing truncated HprK/P was found to be devoid of both HPr kinase and P-Ser-HPr phosphatase activities. When hprK was inactivated, carbon catabolite repression of N-acetylglucosaminidase disappeared, and the lag phase observed during diauxic growth of the wild-type strain on media containing glucose plus either lactose or maltose was strongly diminished. In addition, inducer exclusion exerted by the presence of glucose on maltose transport in the wild-type strain was abolished in the hprK mutant. However, inducer expulsion of methyl beta-D-thiogalactoside triggered by rapidly metabolizable carbon sources was still operative in ptsH mutants altered at Ser-46 of HPr and the hprK mutant, suggesting that, in contrast to the model proposed for inducer expulsion in gram-positive bacteria, P-Ser-HPr might not be involved in this regulatory process.
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Affiliation(s)
- V Dossonnet
- Laboratoire de Génétique des Microorganismes, 78850 Thiverval-Grignon, France
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Huynh PL, Jankovic I, Schnell NF, Brückner R. Characterization of an HPr kinase mutant of Staphylococcus xylosus. J Bacteriol 2000; 182:1895-902. [PMID: 10714994 PMCID: PMC101872 DOI: 10.1128/jb.182.7.1895-1902.2000] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/1999] [Accepted: 12/29/1999] [Indexed: 11/20/2022] Open
Abstract
The Staphylococcus xylosus gene hprK, encoding HPr kinase (HPrK), has been isolated from a genomic library. The HPrK enzyme, purified as a His(6) fusion protein, phosphorylated HPr, the phosphocarrier protein of the bacterial phosphotransferase system, at a serine residue in an ATP-dependent manner, and it also catalyzed the reverse reaction. Therefore, the enzyme constitutes a bifunctional HPr kinase/phosphatase. Insertional inactivation of the gene in the genome of S. xylosus resulted in the concomitant loss of both HPr kinase and His serine-phosphorylated-HPr phosphatase activities in cell extracts, strongly indicating that the HPrK enzyme is also responsible for both reactions in vivo. HPrK deficiency had a profound pleiotropic effect on the physiology of S. xylosus. The hprK mutant strain showed a severe growth defect in complex medium upon addition of glucose. Glucose uptake in glucose-grown cells was strongly enhanced compared with the wild type. Carbon catabolite repression of three tested enzyme activities by glucose, sucrose, and fructose was abolished. These results clearly demonstrate the prominent role of HPr kinase in global control to adjust catabolic capacities of S. xylosus according to the availability of preferred carbon sources.
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Affiliation(s)
- P L Huynh
- Mikrobielle Genetik, Universität Tübingen, D-72076 Tübingen, Germany
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Leskelä S, Wahlström E, Kontinen VP, Sarvas M. Lipid modification of prelipoproteins is dispensable for growth but essential for efficient protein secretion in Bacillus subtilis: characterization of the Lgt gene. Mol Microbiol 1999; 31:1075-85. [PMID: 10096076 DOI: 10.1046/j.1365-2958.1999.01247.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have identified and characterized the Igt gene of Bacillus subtilis. The prelipoprotein diacylglycerol transferase enzyme (Lgt) catalyses the first reaction in lipomodification of bacterial lipoproteins. Inactivation of Igt in B. subtilis by a nonsense mutation (prs-11 mutation) or by disruption was shown here to abolish lipomodification of prelipoproteins completely, as well as the cleavage of signal peptide. However, unlike in Gram-negative bacteria, the Igt mutants of B. subtilis were fully viable. In agreement with this observation, studies of two lipoproteins, PrsA and BlaP, indicated that non-lipomodified precursors of these proteins were functional and translocated across the cytoplasmic membrane. However, there was release of both precursors from cells, resulting in a reduced level of the cell-bound form. We have shown that the reduced level of the PrsA lipoprotein, a foldase involved in protein secretion, caused impaired protein secretion, a prominent phenotype of Igt mutants. There was no indication that non-lipomodified PrsA displayed reduced activity.
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Affiliation(s)
- S Leskelä
- Laboratory of Vaccine Development, National Public Health Institute, Helsinki, Finland
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Abstract
This map is an update of the edition 9 map by Berlyn et al. (M. K. B. Berlyn, K. B. Low, and K. E. Rudd, p. 1715-1902, in F. C. Neidhardt et al., ed., Escherichia coli and Salmonella: cellular and molecular biology, 2nd ed., vol. 2, 1996). It uses coordinates established by the completed sequence, expressed as 100 minutes for the entire circular map, and adds new genes discovered and established since 1996 and eliminates those shown to correspond to other known genes. The latter are included as synonyms. An alphabetical list of genes showing map location, synonyms, the protein or RNA product of the gene, phenotypes of mutants, and reference citations is provided. In addition to genes known to correspond to gene sequences, other genes, often older, that are described by phenotype and older mapping techniques and that have not been correlated with sequences are included.
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Affiliation(s)
- M K Berlyn
- Department of Biology and School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06520-8104, USA.
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Młynarczyk A, Młynarczyk G, Jeljaszewicz J. The genome of Staphylococcus aureus: a review. ZENTRALBLATT FUR BAKTERIOLOGIE : INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY 1998; 287:277-314. [PMID: 9638861 DOI: 10.1016/s0934-8840(98)80165-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The genome of Staphylococcus aureus consists of a single circular chromosome (2.7-2.8 mbp) plus an assortment of extrachromosomal accessory genetic elements: conjugative and nonconjugative plasmids, mobile elements (IS, Tn, Hi), prophages and other variable elements. Plasmids (1-60 kbp) are classified into 4 classes and there are 15 known incompatibility groups. Mobile elements of the genome (0.8-18 kbp) appear in the chromosome or in plasmids of classes II and III. Prophages (45-60 kbp) are integrated in the bacterial chromosome, and they are UV- or mitomycin-inducible. Temperate bacteriophages of S. aureus are members of the Siphoviridae and the serological groups A, B and F occur most frequently. In the paper presented, the characteristics of chromosome, plasmids, transposons and other genetic elements of S. aureus genome are given and an alphabetical list of known genes of this species is included.
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46
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Reizer J, Hoischen C, Titgemeyer F, Rivolta C, Rabus R, Stülke J, Karamata D, Saier MH, Hillen W. A novel protein kinase that controls carbon catabolite repression in bacteria. Mol Microbiol 1998; 27:1157-69. [PMID: 9570401 DOI: 10.1046/j.1365-2958.1998.00747.x] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
HPr(Ser) kinase is the sensor in a multicomponent phosphorelay system that controls catabolite repression, sugar transport and carbon metabolism in gram-positive bacteria. Unlike most other protein kinases, it recognizes the tertiary structure in its target protein, HPr, a phosphocarrier protein of the bacterial phosphotransferase system and a transcriptional cofactor controlling the phenomenon of catabolite repression. We have identified the gene (ptsK) encoding this serine/threonine protein kinase and characterized the purified protein product. Orthologues of PtsK have been identified only in bacteria. These proteins constitute a novel family unrelated to other previously characterized protein phosphorylating enzymes. The Bacillus subtilis kinase is shown to be allosterically activated by metabolites such as fructose 1,6-bisphosphate and inhibited by inorganic phosphate. In contrast to wild-type B. subtilis, the ptsK mutant is insensitive to transcriptional regulation by catabolite repression. The reported results advance our understanding of phosphorylation-dependent carbon control mechanisms in Gram-positive bacteria.
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Affiliation(s)
- J Reizer
- Department of Biology, University of California at San Diego, La Jolla 92093-0116, USA
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47
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Gupta SD, Wu HC, Rick PD. A Salmonella typhimurium genetic locus which confers copper tolerance on copper-sensitive mutants of Escherichia coli. J Bacteriol 1997; 179:4977-84. [PMID: 9260936 PMCID: PMC179352 DOI: 10.1128/jb.179.16.4977-4984.1997] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Three distinct clones from a Salmonella typhimurium genomic library were identified which suppressed the copper-sensitive (Cu(s)) phenotype of cutF mutants of Escherichia coli. One of these clones, pCUTFS2, also increased the copper tolerance of cutA, -C, and -E mutants, as well as that of a lipoprotein diacylglyceryl transferase (lgt) mutant of E. coli. Characterization of pCUTFS2 revealed that the genes responsible for suppression of copper sensitivity (scs) reside on a 4.36-kb DNA fragment located near 25.4 min on the S. typhimurium genome. Sequence analysis of this fragment revealed four open reading frames (ORF120, ORF627, ORF207, and ORF168) that were organized into two operons. One operon consisted of a single gene, scsA (ORF120), whereas the other operon contained the genes scsB (ORF627), scsC (ORF207), and scsD (ORF168). Comparison of the deduced amino acid sequences of the predicted gene products showed that ScsB, ScsC, and ScsD have significant homology to thiol-disulfide interchange proteins (CutA2, DipZ, CycZ, and DsbD) from E. coli and Haemophilus influenzae, to an outer membrane protein (Com1) from Coxiella burnetii, and to thioredoxin and thioredoxin-like proteins, respectively. The two operons were subcloned on compatible plasmids, and complementation analyses indicated that all four proteins are required for the increased copper tolerance of E. coli mutants. In addition, the scs locus also restored lipoprotein modification in lgt mutants of E. coli. Sequence analyses of the S. typhimurium scs genes and adjacent DNAs revealed that the scs locus is flanked by genes with high homology to the cbpA (predicted curved DNA-binding protein) and agp (acid glucose phosphatase) genes of E. coli located at 22.90 min (1,062.07 kb) and 22.95 min (1,064.8 kb) of the E. coli chromosome, respectively. However, examination of the E. coli chromosome revealed that these genes are absent at this locus and no evidence has thus been obtained for the occurrence of the scs locus elsewhere on the genome.
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Affiliation(s)
- S D Gupta
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799, USA
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Sankaran K, Gan K, Rash B, Qi HY, Wu HC, Rick PD. Roles of histidine-103 and tyrosine-235 in the function of the prolipoprotein diacylglyceryl transferase of Escherichia coli. J Bacteriol 1997; 179:2944-8. [PMID: 9139912 PMCID: PMC179058 DOI: 10.1128/jb.179.9.2944-2948.1997] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Phosphatidylglycerol:prolipoprotein diacylglyceryl transferase (Lgt) is the first enzyme in the posttranslational sequence of reactions resulting in the lipid modification of lipoproteins in bacteria. A previous comparison of the primary sequences of the Lgt enzymes from phylogenetically distant bacterial species revealed several highly conserved amino acid sequences throughout the molecule; the most extensive of these was the region 103HGGLIG108 in the Escherichia coli Lgt (H.-Y. Qi, K. Sankaran, K. Gan, and H. C. Wu, J. Bacteriol. 177:6820-6824, 1995). These studies also revealed that the kinetics of inactivation of E. coli Lgt with diethylpyrocarbonate were consistent with the modification of a single essential histidine or tyrosine residue. The current study was conducted in an attempt to identify this essential amino acid residue in order to further define structure-function relationships in Lgt. Accordingly, all of the histidine residues and seven of the tyrosine residues of E. coli Lgt were altered by site-directed mutagenesis, and the in vitro activities of the altered enzymes, as well the abilities of the respective mutant lgt alleles to complement the temperature-sensitive phenotype of E. coli SK634 defective in Lgt activity, were determined. The data obtained from these studies, in conjunction with additional chemical inactivation studies, support the conclusion that His-103 is essential for Lgt activity. These studies also indicated that Tyr-235 plays an important role in the function of this enzyme. Although other histidine and tyrosine residues were not found to be essential for Lgt activity, alterations of His-196 resulted in a significant reduction of in vitro activity.
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Affiliation(s)
- K Sankaran
- Department of Microbiology and Immunology, The Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799, USA
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