1
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Vollmar M, Tirunagari S, Harrus D, Armstrong D, Gáborová R, Gupta D, Afonso MQL, Evans G, Velankar S. Dataset from a human-in-the-loop approach to identify functionally important protein residues from literature. Sci Data 2024; 11:1032. [PMID: 39333508 PMCID: PMC11436914 DOI: 10.1038/s41597-024-03841-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 08/29/2024] [Indexed: 09/29/2024] Open
Abstract
We present a novel system that leverages curators in the loop to develop a dataset and model for detecting structure features and functional annotations at residue-level from standard publication text. Our approach involves the integration of data from multiple resources, including PDBe, EuropePMC, PubMedCentral, and PubMed, combined with annotation guidelines from UniProt, and LitSuggest and HuggingFace models as tools in the annotation process. A team of seven annotators manually curated ten articles for named entities, which we utilized to train a starting PubmedBert model from HuggingFace. Using a human-in-the-loop annotation system, we iteratively developed the best model with commendable performance metrics of 0.90 for precision, 0.92 for recall, and 0.91 for F1-measure. Our proposed system showcases a successful synergy of machine learning techniques and human expertise in curating a dataset for residue-level functional annotations and protein structure features. The results demonstrate the potential for broader applications in protein research, bridging the gap between advanced machine learning models and the indispensable insights of domain experts.
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Affiliation(s)
- Melanie Vollmar
- Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK.
| | - Santosh Tirunagari
- Literature Services, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Deborah Harrus
- Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - David Armstrong
- Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Romana Gáborová
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - Deepti Gupta
- Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Marcelo Querino Lima Afonso
- Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Genevieve Evans
- Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Sameer Velankar
- Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
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2
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Al-Shuaeeb RAA, Yassin AA, Ibrahim MAA, Abd El-Mageed HR, Ghandour MA, Khalil MM. Computer-based identification of olive oil components as a potential inhibitor of neirisaral adhesion a regulatory protein. J Biomol Struct Dyn 2023; 41:1553-1560. [PMID: 34974817 DOI: 10.1080/07391102.2021.2022535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In silico methods such as molecular docking and molecular dynamic (MD) simulations have significant interest due to their ability to identify the protein-ligand interactions at the atomic level. In this work, different computational methods were used to elucidate the ability of some olive oil components to act as Neisseria adhesion A Regulatory protein (NadR) inhibitors. The frontier molecular orbitals (FMOs) and the global properties such as global hardness, electronegativity, and global softness of ten olive oil components (α-Tocopherol, Erythrodiol, Hydroxytyrosol, Linoleic acid, Apigenin, Luteolin, Oleic acid, Oleocanthal, Palmitic acid, and Tyrosol) were reported using Density Functional Theory (DFT) methods. Among all investigated compounds, Erythrodiol, Apigenin, and Luteolin demonstrated the highest binding affinities (-8.72, -7.12, and -8.24 kcal/mol, respectively) against NadR, compared to -8.21 kcal/mol of the native ligand based on molecular docking calculations. ADMET properties and physicochemical features showed that Erythrodiol, Apigenin, and Luteolin have good physicochemical features and can act as drugs candidate. Molecular dynamics (MD) simulations demonstrated that Erythrodiol, Apigenin, and Luteolin show stable binding affinity and molecular interaction with NadR. Further Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) analyses using the MD trajectories also demonstrated the higher binding affinity of Erythrodiol, Apigenin and Luteolin inside NadR protein. The overall study provides a rationale to use Erythrodiol, Apigenin, and Luteolin in the drug development as anti-adhesive drugs lead. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | - A A Yassin
- Chemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
| | - Mahmoud A A Ibrahim
- Computational Chemistry Laboratory, Chemistry Department, Faculty of Science, Minia University, Minia, Egypt
| | - H R Abd El-Mageed
- Micro-Analysis, Environmental Research and Community Affairs Center (MAESC), Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
| | - M A Ghandour
- Chemistry Department, Faculty of Science, Assuit University, Asyut, Egypt
| | - M M Khalil
- Chemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
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3
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Caporaletti F, Pietras Z, Morad V, Mårtensson LG, Gabel F, Wallner B, Martel A, Sunnerhagen M. Small-angle x-ray and neutron scattering of MexR and its complex with DNA supports a conformational selection binding model. Biophys J 2023; 122:408-418. [PMID: 36474441 PMCID: PMC9892617 DOI: 10.1016/j.bpj.2022.11.2949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 09/02/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
In this work, we used small-angle x-ray and neutron scattering to reveal the shape of the protein-DNA complex of the Pseudomonas aeruginosa transcriptional regulator MexR, a member of the multiple antibiotics resistance regulator (MarR) family, when bound to one of its native DNA binding sites. Several MarR-like proteins, including MexR, repress the expression of efflux pump proteins by binding to DNA on regulatory sites overlapping with promoter regions. When expressed, efflux proteins self-assemble to form multiprotein complexes and actively expel highly toxic compounds out of the host organism. The mutational pressure on efflux-regulating MarR family proteins is high since deficient DNA binding leads to constitutive expression of efflux pumps and thereby supports acquired multidrug resistance. Understanding the functional outcome of such mutations and their effects on DNA binding has been hampered by the scarcity of structural and dynamic characterization of both free and DNA-bound MarR proteins. Here, we show how combined neutron and x-ray small-angle scattering of both states in solution support a conformational selection model that enhances MexR asymmetry in binding to one of its promoter-overlapping DNA binding sites.
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Affiliation(s)
- Francesca Caporaletti
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, Sweden; Large Scale Structure, Institute Laue Langevin, Grenoble, France
| | - Zuzanna Pietras
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, Sweden
| | - Vivian Morad
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, Sweden
| | - Lars-Göran Mårtensson
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, Sweden
| | - Frank Gabel
- University Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Björn Wallner
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, Sweden
| | - Anne Martel
- Large Scale Structure, Institute Laue Langevin, Grenoble, France
| | - Maria Sunnerhagen
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, Sweden.
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4
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salah E, El esh H, Abdel-Reheim ES, Abdul-Hamid M. Ameliorative effects of Artemisia and Echinacea extracts against hepato and cardiotoxicity induced by DMBA on albino rats: experimental and molecular docking analyses. BENI-SUEF UNIVERSITY JOURNAL OF BASIC AND APPLIED SCIENCES 2022. [DOI: 10.1186/s43088-022-00286-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Herbal therapy for healing disease has many advantages than drugs. This study investigates the protective efficacy of Artemisia annua (Art) and Echinacea pupurea (Ech) extracts against 7, 12-dimethylbenz (α) anthracene (DMBA) toxicity.
Results
DMBA-treated rats showed a significant increase in the level of serum ALT, AST, LDH and CKMB, also reduction in body weight gain (BWG) ℅, HB, WBCs, RBCs and platelet counts, in addition to histopathological and ultrastructural alterations. Rats treated with Art or Ech after DMBA showed little improvements in the biochemical, hematological, histopathological, ultrastructural and molecular docking results than before DMBA.
Conclusions
This study suggested the ameliorative effect of Ech and Art due to their antioxidant properties, but Ech and Art were more effective if they are given before than after DMBA administration and the marked effect against DMBA toxicity with Ech before DMBA exposure. Also, the molecular docking, molecular properties descriptors, and pharmacoinformatic studies of constituents of extract from Artemisia annua L. and Echinacea purpurea L. exhibited that all studied compounds have better ADMET and physicochemical properties, especially compounds extract from Echinacea purpurea L.
Graphical Abstract
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5
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Baerentsen R, Tang CM, Exley RM. Et tu, Neisseria? Conflicts of Interest Between Neisseria Species. Front Cell Infect Microbiol 2022; 12:913292. [PMID: 35811666 PMCID: PMC9263626 DOI: 10.3389/fcimb.2022.913292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/27/2022] [Indexed: 11/24/2022] Open
Abstract
Neisseria meningitidis and Neisseria gonorrhoeae are two obligate human pathogens that have evolved to be uniquely adapted to their host. The meningococcus is frequently carried asymptomatically in the nasopharynx, while gonococcal infection of the urogenital tract usually elicits a marked local inflammatory response. Other members of the Neisseria genus are abundant in the upper airway where they could engage in co-operative or competitive interactions with both these pathogens. Here, we briefly outline the potential sites of contact between Neisseria spp. in the body, with emphasis on the upper airway, and describe the growing yet circumstantial evidence for antagonism from carriage studies and human volunteer challenge models with Neisseria lactamica. Recent laboratory studies have characterized antagonistic mechanisms that enable competition between Neisseria species. Several of these mechanisms, including Multiple Adhesin family (Mafs), Two Partner Secretion Systems, and Type VI secretion system, involve direct contact between bacteria; the genetic organisation of these systems, and the domain structure of their effector molecules have striking similarities. Additionally, DNA from one species of Neisseria can be toxic to another species, following uptake. More research is needed to define the full repertoire of antagonistic mechanisms in Neisseria spp., their distribution in strains, their range of activity, and contribution to survival in vivo. Understanding the targets of effectors could reveal how antagonistic relationships between close relatives shape subsequent interactions between pathogens and their hosts.
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6
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Veggi D, Malito E, Lo Surdo P, Pansegrau W, Rippa V, Wahome N, Savino S, Masignani V, Pizza M, Bottomley MJ. Structural characterization of a cross-protective natural chimera of factor H binding protein from meningococcal serogroup B strain NL096. Comput Struct Biotechnol J 2022; 20:2070-2081. [PMID: 35601959 PMCID: PMC9079162 DOI: 10.1016/j.csbj.2022.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/11/2022] [Accepted: 04/11/2022] [Indexed: 11/25/2022] Open
Abstract
Invasive meningococcal disease can cause fatal sepsis and meningitis and is a global health threat. Factor H binding protein (fHbp) is a protective antigen included in the two currently available vaccines against serogroup B meningococcus (MenB). FHbp is a remarkably variable surface-exposed meningococcal virulence factor with over 1300 different amino acid sequences identified so far. Based on this variability, fHbp has been classified into three variants, two subfamilies or nine modular groups, with low degrees of cross-protective activity. Here, we report the crystal structure of a natural fHbp cross-variant chimera, named variant1-2,3.x expressed by the MenB clinical isolate NL096, at 1.2 Å resolution, the highest resolution of any fHbp structure reported to date. We combined biochemical, site-directed mutagenesis and computational biophysics studies to deeply characterize this rare chimera. We determined the structure to be composed of two adjacent domains deriving from the three variants and determined the molecular basis of its stability, ability to bind Factor H and to adopt the canonical three-dimensional fHbp structure. These studies guided the design of loss-of-function mutations with potential for even greater immunogenicity. Moreover, this study represents a further step in the understanding of the fHbp biological and immunological evolution in nature. The chimeric variant1-2,3.x fHbp protein emerges as an intriguing cross-protective immunogen and suggests that identification of such naturally occurring hybrid proteins may result in stable and cross-protective immunogens when seeking to design and develop vaccines against highly variable pathogens.
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Affiliation(s)
- Daniele Veggi
- Corresponding author at: GSK Vaccines srl, Via Fiorentina 1, Siena 53100, Italy.
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7
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Permsirivisarn P, Yuenyao A, Pramanpol N, Charoenwattanasatien R, Suginta W, Chaiyen P, Pakotiprapha D. Mechanism of transcription regulation by Acinetobacter baumannii HpaR in the catabolism of p-hydroxyphenylacetate. FEBS J 2021; 289:3217-3240. [PMID: 34967505 DOI: 10.1111/febs.16340] [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: 04/26/2021] [Revised: 12/16/2021] [Accepted: 12/29/2021] [Indexed: 11/25/2022]
Abstract
HpaR is a transcription regulator in the MarR family that controls the expression of the gene cluster responsible for conversion of p-hydroxyphenylacetate to pyruvate and succinate for cellular metabolism. Here, we report the biochemical and structural characterization of Acinetobacter baumannii HpaR (AbHpaR) and its complex with cognate DNA. Our study revealed that AbHpaR binds upstream of the divergently transcribed hpaA gene and the meta-cleavage operon, as well as the hpaR gene, thereby repressing their transcription by blocking access of RNA polymerase. Structural analysis of AbHpaR-DNA complex revealed that the DNA binding specificity can be achieved via a combination of both direct and indirect DNA sequence readouts. DNA binding of AbHpaR is weakened by 3,4-dihydroxyphenylacetate (DHPA), which is the substrate of the meta-cleavage reactions; this likely leads to expression of the target genes. Based on our findings, we propose a model for how A. baumannii controls transcription of HPA-metabolizing genes, which highlights the independence of global catabolite repression and could be beneficial for metabolic engineering towards bioremediation applications.
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Affiliation(s)
- Permkun Permsirivisarn
- Doctor of Philosophy Program in Biochemistry (International Program), Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.,Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.,Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Anan Yuenyao
- Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Nuttawan Pramanpol
- Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima, 30000, Thailand.,National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
| | | | - Wipa Suginta
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | - Danaya Pakotiprapha
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.,Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
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8
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Hwang J, Park SH, Lee CW, Do H, Shin SC, Kim HW, Lee SG, Park HH, Kwon S, Lee JH. Crystal structure of a MarR family protein from the psychrophilic bacterium Paenisporosarcina sp. TG-14 in complex with a lipid-like molecule. IUCRJ 2021; 8:842-852. [PMID: 34584745 PMCID: PMC8420766 DOI: 10.1107/s2052252521005704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/02/2021] [Indexed: 06/13/2023]
Abstract
MarR family proteins regulate the transcription of multiple antibiotic-resistance genes and are widely found in bacteria and archaea. Recently, a new MarR family gene was identified by genome analysis of the psychrophilic bacterium Paenisporosarcina sp. TG-14, which was isolated from sediment-laden basal ice in Antarctica. In this study, the crystal structure of the MarR protein from Paenisporosarcina sp. TG-14 (PaMarR) was determined at 1.6 Å resolution. In the crystal structure, a novel lipid-type compound (palmitic acid) was found in a deep cavity, which was assumed to be an effector-binding site. Comparative structural analysis of homologous MarR family proteins from a mesophile and a hyperthermophile showed that the DNA-binding domain of PaMarR exhibited relatively high mobility, with a disordered region between the β1 and β2 strands. In addition, structural comparison with other homologous complex structures suggests that this structure constitutes a conformer transformed by palmitic acid. Biochemical analysis also demonstrated that PaMarR binds to cognate DNA, where PaMarR is known to recognize two putative binding sites depending on its molar concentration, indicating that PaMarR binds to its cognate DNA in a stoichiometric manner. The present study provides structural information on the cold-adaptive MarR protein with an aliphatic compound as its putative effector, extending the scope of MarR family protein research.
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Affiliation(s)
- Jisub Hwang
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Republic of Korea
- Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea
| | - Sun-Ha Park
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Republic of Korea
| | - Chang Woo Lee
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Republic of Korea
| | - Hackwon Do
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Republic of Korea
| | - Seung Chul Shin
- Division of Life Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea
| | - Han-Woo Kim
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Republic of Korea
- Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea
| | - Sung Gu Lee
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Republic of Korea
- Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea
| | - Hyun Ho Park
- College of Pharmacy, Chung-Ang University, Dongjak-gu, Seoul 06974, Republic of Korea
| | - Sunghark Kwon
- Department of Biotechnology, Konkuk University, Chungju, Chungbuk 27478, Republic of Korea
| | - Jun Hyuck Lee
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Republic of Korea
- Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea
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9
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Rafi MO, Al-Khafaji K, Tok TT, Rahman MS. Computer-based identification of potential compounds from Salviae miltiorrhizae against Neirisaral adhesion A regulatory protein. J Biomol Struct Dyn 2020; 40:4301-4313. [PMID: 33289608 DOI: 10.1080/07391102.2020.1856189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In silico studies are attracting considerable interest due to their ability to understand protein-ligand interactions at the atomic level. The main principal tools of this in silico analyses are molecular docking and molecular dynamic (MD) simulation. This paper examines how can natural compounds that are derived from Salviae miltiorrhizae to block Neisseria adhesion A Regulatory protein (NadR). In molecular docking analysis, only four compounds were found in higher binding affinity with NadR among 10 candidates (tanshinol B, tanshinol A, lithospermic acid and tournefolal were -7.61, -7.56, -8.22 and -7.81 kcal/mol, respectively, compared to -7.23 kcal/mol of native ligand). Absorption, distribution, metabolism, excretion (ADME) and toxicity properties, medicinal chemistry profile, and physicochemical features were displayed that tournefolal contains good properties to work as a safe and good anti-adhesive drug. Therefore, the complexes of these four ligands with NadR protein were subjected to 100 ns of MD simulation. RMSD, RMSF, RG and hydrogen bonding exhibited that tournefolal showed stable binding affinity and molecular interaction with NadR protein. In light of these results, there is now a need to conduct much more in vitro and in vivo studies about the efficacy of tournefolal.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Md Oliullah Rafi
- Department of Genetic Engineering and Biotechnology, Jashore University of Science and Technology, Jashore, Bangladesh
| | - Khattab Al-Khafaji
- Faculty of Arts and Sciences, Department of Chemistry, Gaziantep University, Gaziantep, Turkey
| | - Tugba Taskin Tok
- Faculty of Arts and Sciences, Department of Chemistry, Gaziantep University, Gaziantep, Turkey.,Institute of Health Sciences, Department of Bioinformatics and Computational Biology, Gaziantep University, Gaziantep, Turkey
| | - Md Shahedur Rahman
- Department of Genetic Engineering and Biotechnology, Jashore University of Science and Technology, Jashore, Bangladesh
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10
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Moraxella catarrhalis phase-variable loci show differences in expression during conditions relevant to disease. PLoS One 2020; 15:e0234306. [PMID: 32555615 PMCID: PMC7302503 DOI: 10.1371/journal.pone.0234306] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 05/22/2020] [Indexed: 11/29/2022] Open
Abstract
Moraxella catarrhalis is a human-adapted, opportunistic bacterial pathogen of the respiratory mucosa. Although asymptomatic colonization of the nasopharynx is common, M. catarrhalis can ascend into the middle ear, where it is a prevalent causative agent of otitis media in children, or enter the lower respiratory tract, where it is associated with acute exacerbations of chronic obstructive pulmonary disease in adults. Phase variation is the high frequency, random, reversible switching of gene expression that allows bacteria to adapt to different host microenvironments and evade host defences, and is most commonly mediated by simple DNA sequence repeats. Bioinformatic analysis of five closed M. catarrhalis genomes identified 17 unique simple DNA sequence repeat tracts that were variable between strains, indicating the potential to mediate phase variable expression of the associated genes. Assays designed to assess simple sequence repeat variation under conditions mimicking host infection demonstrated that phase variation of uspA1 (ubiquitous surface protein A1) from high to low expression occurs over 72 hours of biofilm passage, while phase variation of uspA2 (ubiquitous surface protein A2) to high expression variants occurs during repeated exposure to human serum, as measured by mRNA levels. We also identify and confirm the variable expression of two novel phase variable genes encoding a Type III DNA methyltransferase (modO), and a conserved hypothetical permease (MC25239_RS00020). These data reveal the repertoire of phase variable genes mediated by simple sequence repeats in M. catarrhalis and demonstrate that modulation of expression under conditions mimicking human infection is attributed to changes in simple sequence repeat length.
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11
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Conformational equilibrium defines the variable induction of the multidrug-binding transcriptional repressor QacR. Proc Natl Acad Sci U S A 2019; 116:19963-19972. [PMID: 31527244 DOI: 10.1073/pnas.1906129116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
QacR, a multidrug-binding transcriptional repressor in pathogenic bacteria Staphylococcus aureus, modulates the transcriptional level of the multidrug transporter gene, qacA, in response to engaging a set of diverse ligands. However, the structural basis that defines the variable induction level remains unknown. Here, we reveal that the conformational equilibrium between the repressive and inducive conformations in QacR defines the induction level of the transporter gene. In addition, the unligated QacR is already partly populated in the inducive conformation, allowing the basal expression of the transporter. We also showed that, in the known constitutively active QacR mutants, the equilibrium is shifted more toward the inducive conformation, even in the unligated state. These results highlight the unexpected structural mechanism, connecting the promiscuous multidrug binding to the variable transcriptional regulation of QacR, which provide clues to dysfunctioning of the multidrug resistance systems.
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12
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Capdevila DA, Huerta F, Edmonds KA, Le MT, Wu H, Giedroc DP. Tuning site-specific dynamics to drive allosteric activation in a pneumococcal zinc uptake regulator. eLife 2018; 7:37268. [PMID: 30328810 PMCID: PMC6224198 DOI: 10.7554/elife.37268] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 10/16/2018] [Indexed: 11/25/2022] Open
Abstract
MarR (multiple antibiotic resistance repressor) family proteins are bacterial repressors that regulate transcription in response to a wide range of chemical signals. Although specific features of MarR family function have been described, the role of atomic motions in MarRs remains unexplored thus limiting insights into the evolution of allostery in this ubiquitous family of repressors. Here, we provide the first experimental evidence that internal dynamics play a crucial functional role in MarR proteins. Streptococcus pneumoniae AdcR (adhesin-competence repressor) regulates ZnII homeostasis and ZnII functions as an allosteric activator of DNA binding. ZnII coordination triggers a transition from somewhat independent domains to a more compact structure. We identify residues that impact allosteric activation on the basis of ZnII-induced perturbations of atomic motions over a wide range of timescales. These findings appear to reconcile the distinct allosteric mechanisms proposed for other MarRs and highlight the importance of conformational dynamics in biological regulation.
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Affiliation(s)
| | - Fidel Huerta
- Department of Chemistry, Indiana University, Bloomington, United States.,Graduate Program in Biochemistry, Indiana University, Bloomington, United States
| | | | - My Tra Le
- Department of Chemistry, Indiana University, Bloomington, United States
| | - Hongwei Wu
- Department of Chemistry, Indiana University, Bloomington, United States
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, United States.,Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, United States
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13
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Liguori A, Dello Iacono L, Maruggi G, Benucci B, Merola M, Lo Surdo P, López-Sagaseta J, Pizza M, Malito E, Bottomley MJ. NadA3 Structures Reveal Undecad Coiled Coils and LOX1 Binding Regions Competed by Meningococcus B Vaccine-Elicited Human Antibodies. mBio 2018; 9:e01914-18. [PMID: 30327444 PMCID: PMC6191539 DOI: 10.1128/mbio.01914-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 12/22/2022] Open
Abstract
Neisseria meningitidis serogroup B (MenB) is a major cause of sepsis and invasive meningococcal disease. A multicomponent vaccine, 4CMenB, is approved for protection against MenB. Neisserial adhesin A (NadA) is one of the main vaccine antigens, acts in host cell adhesion, and may influence colonization and invasion. Six major genetic variants of NadA exist and can be classified into immunologically distinct groups I and II. Knowledge of the crystal structure of the 4CMenB vaccine component NadA3 (group I) would improve understanding of its immunogenicity, folding, and functional properties and might aid antigen design. Here, X-ray crystallography, biochemical, and cellular studies were used to deeply characterize NadA3. The NadA3 crystal structure is reported; it revealed two unexpected regions of undecad coiled-coil motifs and other conformational differences from NadA5 (group II) not predicted by previous analyses. Structure-guided engineering was performed to increase NadA3 thermostability, and a second crystal structure confirmed the improved packing. Functional NadA3 residues mediating interactions with human receptor LOX-1 were identified. Also, for two protective vaccine-elicited human monoclonal antibodies (5D11, 12H11), we mapped key NadA3 epitopes. These vaccine-elicited human MAbs competed binding of NadA3 to LOX-1, suggesting their potential to inhibit host-pathogen colonizing interactions. The data presented provide a significant advance in the understanding of the structure, immunogenicity and function of NadA, one of the main antigens of the multicomponent meningococcus B vaccine.IMPORTANCE The bacterial microbe Neisseria meningitidis serogroup B (MenB) is a major cause of devastating meningococcal disease. An approved multicomponent vaccine, 4CMenB, protects against MenB. Neisserial adhesin A (NadA) is a key vaccine antigen and acts in host cell-pathogen interactions. We investigated the 4CMenB vaccine component NadA3 in order to improve the understanding of its immunogenicity, structure, and function and to aid antigen design. We report crystal structures of NadA3, revealing unexpected structural motifs, and other conformational differences from the NadA5 orthologue studied previously. We performed structure-based antigen design to engineer increased NadA3 thermostability. Functional NadA3 residues mediating interactions with the human receptor LOX-1 and vaccine-elicited human antibodies were identified. These antibodies competed binding of NadA3 to LOX-1, suggesting their potential to inhibit host-pathogen colonizing interactions. Our data provide a significant advance in the overall understanding of the 4CMenB vaccine antigen NadA.
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Affiliation(s)
| | | | | | | | - Marcello Merola
- GSK, Siena, Italy
- Department of Biology, University of Naples Federico II, Naples, Italy
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Yuenyao A, Petchyam N, Kamonsutthipaijit N, Chaiyen P, Pakotiprapha D. Crystal structure of the flavin reductase of Acinetobacter baumannii p-hydroxyphenylacetate 3-hydroxylase (HPAH) and identification of amino acid residues underlying its regulation by aromatic ligands. Arch Biochem Biophys 2018; 653:24-38. [PMID: 29940152 DOI: 10.1016/j.abb.2018.06.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 06/07/2018] [Accepted: 06/21/2018] [Indexed: 10/28/2022]
Abstract
The first step in the degradation of p-hydroxyphenylacetic acid (HPA) is catalyzed by the two-component enzyme p-hydroxyphenylacetate 3-hydroxylase (HPAH). The two components of Acinetobacter baumannii HPAH are known as C1 and C2, respectively. C1 is a flavin reductase that uses NADH to generate reduced flavin mononucleotide (FMNH-), which is used by C2 in the hydroxylation of HPA. Interestingly, although HPA is not directly involved in the reaction catalyzed by C1, the presence of HPA dramatically increases the FMN reduction rate. Amino acid sequence analysis revealed that C1 contains two domains: an N-terminal flavin reductase domain, and a C-terminal MarR domain. Although MarR proteins typically function as transcription regulators, the MarR domain of C1 was found to play an auto-inhibitory role. Here, we report a crystal structure of C1 and small-angle X-ray scattering (SAXS) studies that revealed that C1 undergoes a substantial conformational change in the presence of HPA, concomitant with the increase in the rate of flavin reduction. Amino acid residues that are important for HPA binding and regulation of C1 activity were identified by site-directed mutagenesis. Amino acid sequence similarity analysis revealed several as yet uncharacterized flavin reductases with N- or C-terminal fusions.
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Affiliation(s)
- Anan Yuenyao
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Nopphon Petchyam
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | | | - Pimchai Chaiyen
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology Faculty of Science, Mahidol University, Bangkok, 10400, Thailand; School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | - Danaya Pakotiprapha
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.
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15
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Deochand DK, Grove A. MarR family transcription factors: dynamic variations on a common scaffold. Crit Rev Biochem Mol Biol 2017; 52:595-613. [PMID: 28670937 DOI: 10.1080/10409238.2017.1344612] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Members of the multiple antibiotic resistance regulator (MarR) family of transcription factors are critical for bacterial cells to respond to chemical signals and to convert such signals into changes in gene activity. Obligate dimers belonging to the winged helix-turn-helix protein family, they are critical for regulation of a variety of functions, including degradation of organic compounds and control of virulence gene expression. The conventional regulatory paradigm is based on a genomic locus in which the gene encoding the MarR protein is divergently oriented from a gene under its control; MarR binding to the intergenic region controls expression of both genes by changing the interaction of RNA polymerase with gene promoters. MarR protein oxidation or binding of a small molecule ligand adversely affects DNA binding, resulting in altered expression of the divergent genes. The generality of this simple paradigm, including the regulation of Escherichia coli MarR by direct binding of antibiotics, has been challenged by reports published in recent years. In addition, structural and biochemical analyses of ligand binding to numerous MarR homologs are converging to identify a shared ligand-binding "hot-spot". This review highlights recent research advances that point to shared features, yet at the same time highlights the remarkable flexibility with which members of this protein family implement responses to inducing signals. A more comprehensive understanding of protein function will pave the way towards the development of both antibacterial agents and biosensors that are based on MarR family proteins.
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Affiliation(s)
- Dinesh K Deochand
- a Department of Biological Sciences , Louisiana State University , Baton Rouge , LA , USA
| | - Anne Grove
- a Department of Biological Sciences , Louisiana State University , Baton Rouge , LA , USA
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16
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Grove A. Regulation of Metabolic Pathways by MarR Family Transcription Factors. Comput Struct Biotechnol J 2017; 15:366-371. [PMID: 28694934 PMCID: PMC5487221 DOI: 10.1016/j.csbj.2017.06.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/05/2017] [Accepted: 06/08/2017] [Indexed: 01/24/2023] Open
Abstract
Bacteria have evolved sophisticated mechanisms for regulation of metabolic pathways. Such regulatory circuits ensure that anabolic pathways remain repressed unless final products are in short supply and that catabolic enzymes are not produced in absence of their substrates. The precisely tuned gene activity underlying such circuits is in the purview of transcription factors that may bind pathway intermediates, which in turn modulate transcription factor function and therefore gene expression. This review focuses on the role of ligand-responsive MarR family transcription factors in controlling expression of genes encoding metabolic enzymes and the mechanisms by which such control is exerted. Prospects for exploiting these transcription factors for optimization of gene expression for metabolic engineering and for the development of biosensors are considered.
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Affiliation(s)
- Anne Grove
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
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17
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Gupta A, Fuentes SM, Grove A. Redox-Sensitive MarR Homologue BifR from Burkholderia thailandensis Regulates Biofilm Formation. Biochemistry 2017; 56:2315-2327. [PMID: 28406615 DOI: 10.1021/acs.biochem.7b00103] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biofilm formation by pathogenic Burkholderia species is a serious complication as it renders the bacteria resistant to antibiotics and host defenses. Using B. thailandensis, we report here a novel redox-sensitive member of the multiple antibiotic resistance regulator (MarR) protein family, BifR, which represses biofilm formation. BifR is encoded as part of the emrB-bifR operon; emrB-bifR is divergent to ecsC, which encodes a putative LasA protease. In Pseudomonas aeruginosa, LasA has been implicated in virulence by contributing to cleavage of elastase. BifR repressed the expression of ecsC and emrB-bifR, and expression was further repressed under oxidizing conditions. BifR bound two sites in the intergenic region between ecsC and emrB-bifR with nanomolar affinity under both reducing and oxidizing conditions; however, oxidized BifR formed a disulfide-linked dimer-of-dimers, a covalent linkage that was absent in BifR-C104A in which the redox-active cysteine was replaced with alanine. BifR also repressed an operon encoding enzymes required for synthesis of phenazine antibiotics, which function as alternate respiratory electron receptors, and inactivation of bifR resulted in enhanced biofilm formation. Taken together, our data suggest that BifR functions to control LasA production and expression of genes involved in biofilm formation, in part by regulating synthesis of alternate electron acceptors that promote survival in the oxygen-limiting environment of a biofilm. The correlation between increased repression of emrB-bifR under oxidative conditions and the formation of a covalently linked BifR dimer-of-dimers suggests that BifR may modulate gene activity in response to cellular redox state.
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Affiliation(s)
- Ashish Gupta
- Department of Biological Sciences, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Stanley M Fuentes
- Department of Biological Sciences, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Anne Grove
- Department of Biological Sciences, Louisiana State University , Baton Rouge, Louisiana 70803, United States
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18
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Takeuchi K, Imai M, Shimada I. Dynamic equilibrium on DNA defines transcriptional regulation of a multidrug binding transcriptional repressor, LmrR. Sci Rep 2017; 7:267. [PMID: 28325892 PMCID: PMC5428041 DOI: 10.1038/s41598-017-00257-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/14/2017] [Indexed: 11/09/2022] Open
Abstract
LmrR is a multidrug binding transcriptional repressor that controls the expression of a major multidrug transporter, LmrCD, in Lactococcus lactis. Promiscuous compound ligations reduce the affinity of LmrR for the lmrCD operator by several fold to release the transcriptional repression; however, the affinity reduction is orders of magnitude smaller than that of typical transcriptional repressors. Here, we found that the transcriptional regulation of LmrR is achieved through an equilibrium between the operator-bound and non-specific DNA-adsorption states in vivo. The effective dissociation constant of LmrR for the lmrCD operator under the equilibrium is close to the endogenous concentration of LmrR, which allows a substantial reduction of LmrR occupancy upon compound ligations. Therefore, LmrR represents a dynamic type of transcriptional regulation of prokaryotic multidrug resistance systems, where the small affinity reduction induced by compounds is coupled to the functional relocalization of the repressor on the genomic DNA via nonspecific DNA adsorption.
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Affiliation(s)
- Koh Takeuchi
- Biomedicinal Information Research Center & Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Aomi 2-3-26, Koto-ku, Tokyo, 135-0064, Japan.,PRESTO, JST, Aomi 2-3-26, Koto-ku, Tokyo, 135-0064, Japan
| | - Misaki Imai
- Research and Development Department, Japan Biological Informatics Consortium, Aomi 2-3-26, Koto-ku, Tokyo, 135-0064, Japan
| | - Ichio Shimada
- Biomedicinal Information Research Center & Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Aomi 2-3-26, Koto-ku, Tokyo, 135-0064, Japan. .,Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
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19
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Zhu R, Hao Z, Lou H, Song Y, Zhao J, Chen Y, Zhu J, Chen PR. Structural characterization of the DNA-binding mechanism underlying the copper(II)-sensing MarR transcriptional regulator. J Biol Inorg Chem 2017; 22:685-693. [DOI: 10.1007/s00775-017-1442-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/03/2017] [Indexed: 01/29/2023]
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20
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Tan A, Atack JM, Jennings MP, Seib KL. The Capricious Nature of Bacterial Pathogens: Phasevarions and Vaccine Development. Front Immunol 2016; 7:586. [PMID: 28018352 PMCID: PMC5149525 DOI: 10.3389/fimmu.2016.00586] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 11/28/2016] [Indexed: 12/11/2022] Open
Abstract
Infectious diseases are a leading cause of morbidity and mortality worldwide, and vaccines are one of the most successful and cost-effective tools for disease prevention. One of the key considerations for rational vaccine development is the selection of appropriate antigens. Antigens must induce a protective immune response, and this response should be directed to stably expressed antigens so the target microbe can always be recognized by the immune system. Antigens with variable expression, due to environmental signals or phase variation (i.e., high frequency, random switching of expression), are not ideal vaccine candidates because variable expression could lead to immune evasion. Phase variation is often mediated by the presence of highly mutagenic simple tandem DNA repeats, and genes containing such sequences can be easily identified, and their use as vaccine antigens reconsidered. Recent research has identified phase variably expressed DNA methyltransferases that act as global epigenetic regulators. These phase-variable regulons, known as phasevarions, are associated with altered virulence phenotypes and/or expression of vaccine candidates. As such, genes encoding candidate vaccine antigens that have no obvious mechanism of phase variation may be subject to indirect, epigenetic control as part of a phasevarion. Bioinformatic and experimental studies are required to elucidate the distribution and mechanism of action of these DNA methyltransferases, and most importantly, whether they mediate epigenetic regulation of potential and current vaccine candidates. This process is essential to define the stably expressed antigen target profile of bacterial pathogens and thereby facilitate efficient, rational selection of vaccine antigens.
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Affiliation(s)
- Aimee Tan
- Institute for Glycomics, Griffith University , Gold Coast, QLD , Australia
| | - John M Atack
- Institute for Glycomics, Griffith University , Gold Coast, QLD , Australia
| | - Michael P Jennings
- Institute for Glycomics, Griffith University , Gold Coast, QLD , Australia
| | - Kate L Seib
- Institute for Glycomics, Griffith University , Gold Coast, QLD , Australia
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21
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Krause M, Neubauer A, Neubauer P. The fed-batch principle for the molecular biology lab: controlled nutrient diets in ready-made media improve production of recombinant proteins in Escherichia coli. Microb Cell Fact 2016; 15:110. [PMID: 27317421 PMCID: PMC4912726 DOI: 10.1186/s12934-016-0513-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 06/09/2016] [Indexed: 11/10/2022] Open
Abstract
While the nutrient limited fed-batch technology is the standard of the cultivation of microorganisms and production of heterologous proteins in industry, despite its advantages in view of metabolic control and high cell density growth, shaken batch cultures are still the standard for protein production and expression screening in molecular biology and biochemistry laboratories. This is due to the difficulty and expenses to apply a controlled continuous glucose feed to shaken cultures. New ready-made growth media, e.g. by biocatalytic release of glucose from a polymer, offer a simple solution for the application of the fed-batch principle in shaken plate and flask cultures. Their wider use has shown that the controlled diet not only provides a solution to obtain significantly higher cell yields, but also in many cases folding of the target protein is improved by the applied lower growth rates; i.e. final volumetric yields for the active protein can be a multiple of what is obtained in complex medium cultures. The combination of the conventional optimization approaches with new and easy applicable growth systems has revolutionized recombinant protein production in Escherichia coli in view of product yield, culture robustness as well as significantly increased cell densities. This technical development establishes the basis for successful miniaturization and parallelization which is now an important tool for synthetic biology and protein engineering approaches. This review provides an overview of the recent developments, results and applications of advanced growth systems which use a controlled glucose release as substrate supply.
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Affiliation(s)
- Mirja Krause
- />Laboratory of Bioprocess Engineering, Department of Biotechnology, Chair of Bioprocess Engineering, Technische Universität Berlin, Ackerstr. 76, ACK 24, 13355 Berlin, Germany
- />Laboratory of Developmental Biology, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Aapistie 5A, 90220 Oulu, Finland
| | | | - Peter Neubauer
- />Laboratory of Bioprocess Engineering, Department of Biotechnology, Chair of Bioprocess Engineering, Technische Universität Berlin, Ackerstr. 76, ACK 24, 13355 Berlin, Germany
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