1
|
Kaur R, Wetmore SD. Is Metal Stabilization of the Leaving Group Required or Can Lysine Facilitate Phosphodiester Bond Cleavage in Nucleic Acids? A Computational Study of EndoV. J Chem Inf Model 2024; 64:944-959. [PMID: 38253321 DOI: 10.1021/acs.jcim.3c01775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Endonuclease V (EndoV) is a single-metal-dependent enzyme that repairs deaminated DNA nucleobases in cells by cleaving the phosphodiester bond, and this enzyme has proven to be a powerful tool in biotechnology and medicine. The catalytic mechanism used by EndoV must be understood to design new disease detection and therapeutic solutions and further exploit the enzyme in interdisciplinary applications. This study has used a mixed molecular dynamics (MD) and quantum mechanics/molecular mechanics (QM/MM) approach to compare eight distinct catalytic pathways and provides the first proposed mechanism for bacterial EndoV. The calculations demonstrate that mechanisms involving either direct or indirect metal coordination to the leaving group of the substrate previously proposed for other nucleases are unlikely for EndoV, regardless of the general base (histidine, aspartate, and substrate phosphate moiety). Instead, distinct catalytic pathways are characterized for EndoV that involve K139 stabilizing the leaving group, a metal-coordinated water stabilizing the transition structure, and either H214 or a substrate phosphate group activating the water nucleophile. In silico K139A and H214A mutational results support the newly proposed roles of these residues. Although this is a previously unseen combination of general base, general acid, and metal-binding architecture for a one-metal-dependent endonuclease, our proposed catalytic mechanisms are fully consistent with experimental kinetic, structural, and mutational data. In addition to substantiating a growing body of literature, suggesting that one metal is enough to catalyze P-O bond cleavage in nucleic acids, this new fundamental understanding of the catalytic function will promote the exploration of new and improved applications of EndoV.
Collapse
Affiliation(s)
- Rajwinder Kaur
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
| |
Collapse
|
2
|
Garcia Gonzalez J, Hernandez FJ. Nuclease activity: an exploitable biomarker in bacterial infections. Expert Rev Mol Diagn 2022; 22:265-294. [PMID: 35240900 DOI: 10.1080/14737159.2022.2049249] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION In the increasingly challenging field of clinical microbiology, diagnosis is a cornerstone whose accuracy and timing are crucial for the successful management, therapy, and outcome of infectious diseases. Currently employed biomarkers of infectious diseases define the scope and limitations of diagnostic techniques. As such, expanding the biomarker catalog is crucial to address unmet needs and bring about novel diagnostic functionalities and applications. AREAS COVERED This review describes the extracellular nucleases of 15 relevant bacterial pathogens and discusses the potential use of nuclease activity as a diagnostic biomarker. Articles were searched for in PubMed using terms: "nuclease", "bacteria", "nuclease activity" or "biomarker". For overview sections, original and review articles between 2000 and 2019 were searched for using terms: "infections", "diagnosis", "bacterial", "burden", "challenges". Informative articles were selected. EXPERT OPINION Using the catalytic activity of nucleases offers new possibilities compared to established biomarkers. Nucleic acid activatable reporters in combination with different transduction platforms and delivery methods can be used to detect disease-associated nuclease activity patterns in vitro and in vivo for prognostic and diagnostic applications. Even when these patterns are not obvious or of unknown etiology, screening platforms could be used to identify new disease reporters.
Collapse
Affiliation(s)
- Javier Garcia Gonzalez
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.,Wallenberg Centre for Molecular Medicine (WCMM), Linköping, Sweden.,Nucleic Acids Technologies Laboratory (NAT-lab), Linköping University, Linköping, Sweden
| | - Frank J Hernandez
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.,Wallenberg Centre for Molecular Medicine (WCMM), Linköping, Sweden.,Nucleic Acids Technologies Laboratory (NAT-lab), Linköping University, Linköping, Sweden
| |
Collapse
|
3
|
Mahato C, Menon S, Singh A, Afrose SP, Mondal J, Das D. Short Peptide-based Cross-β Amyloids Exploit Dual Residues for Phosphoesterase like Activity. Chem Sci 2022; 13:9225-9231. [PMID: 36092997 PMCID: PMC9384705 DOI: 10.1039/d2sc03205h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/17/2022] [Indexed: 11/21/2022] Open
Abstract
Herein, we report that short peptides are capable of exploiting their anti-parallel registry to access cross-β stacks to expose more than one catalytic residue, exhibiting the traits of advanced binding pockets of enzymes. Binding pockets decorated with more than one catalytic residue facilitate substrate binding and process kinetically unfavourable chemical transformations. The solvent-exposed guanidinium and imidazole moieties on the cross-β microphases synergistically bind to polarise and hydrolyse diverse kinetically stable model substrates of nucleases and phosphatase. Mutation of either histidine or arginine results in a drastic decline in the rate of hydrolysis. These results not only support the argument of short amyloid peptides as the earliest protein folds but also suggest their interactions with nucleic acid congeners, foreshadowing the mutualistic biopolymer relationships that fueled the chemical emergence of life. Amyloid based short peptide assemblies use antiparallel registry to expose multiple catalytic residues to bind and cleave kinetically stable phosphoester bonds of nucleic acid congeners, foreshadowing interactions of protein folds with nucleic acids.![]()
Collapse
Affiliation(s)
- Chiranjit Mahato
- Department of Chemical Sciences & Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata Mohanpur West Bengal 741246 India
| | - Sneha Menon
- Tata Institute of Fundamental Research Hyderabad Telangana 500046 India
| | - Abhishek Singh
- Department of Chemical Sciences & Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata Mohanpur West Bengal 741246 India
| | - Syed Pavel Afrose
- Department of Chemical Sciences & Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata Mohanpur West Bengal 741246 India
| | - Jagannath Mondal
- Tata Institute of Fundamental Research Hyderabad Telangana 500046 India
| | - Dibyendu Das
- Department of Chemical Sciences & Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata Mohanpur West Bengal 741246 India
| |
Collapse
|
4
|
Structure and function of the Ecto-Nucleotide Pyrophosphatase-Phosphodiesterase (ENPP) family: tidying up diversity. J Biol Chem 2021; 298:101526. [PMID: 34958798 PMCID: PMC8808174 DOI: 10.1016/j.jbc.2021.101526] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 12/11/2022] Open
Abstract
Ecto-nucleotide pyrophosphatase/phosphodiesterase (ENPP) family members (ENPP1–7) have been implicated in key biological and pathophysiological processes, including nucleotide and phospholipid signaling, bone mineralization, fibrotic diseases, and tumor-associated immune cell infiltration. ENPPs are single-pass transmembrane ecto-enzymes, with notable exceptions of ENPP2 (Autotaxin) and ENNP6, which are secreted and glycosylphosphatidylinositol (GPI)-anchored, respectively. ENNP1 and ENNP2 are the best characterized and functionally the most interesting members. Here, we review the structural features of ENPP1–7 to understand how they evolved to accommodate specific substrates and mediate different biological activities. ENPPs are defined by a conserved phosphodiesterase (PDE) domain. In ENPP1–3, the PDE domain is flanked by two N-terminal somatomedin B-like domains and a C-terminal inactive nuclease domain that confers structural stability, whereas ENPP4–7 only possess the PDE domain. Structural differences in the substrate-binding site endow each protein with unique characteristics. Thus, ENPP1, ENPP3, ENPP4, and ENPP5 hydrolyze nucleotides, whereas ENPP2, ENPP6, and ENNP7 evolved as phospholipases through adaptions in the catalytic domain. These adaptations explain the different biological and pathophysiological functions of individual members. Understanding the ENPP members as a whole advances our insights into common mechanisms, highlights their functional diversity, and helps to explore new biological roles.
Collapse
|
5
|
Park KH, Yoon SM, Song HN, Yang JH, Ryu SE, Woo EJ. Crystal structure of the mouse endonuclease G. Biochem Biophys Res Commun 2020; 526:35-40. [PMID: 32192768 DOI: 10.1016/j.bbrc.2020.03.060] [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: 03/06/2020] [Accepted: 03/10/2020] [Indexed: 10/24/2022]
Abstract
Endonuclease G (EndoG) is a mitochondrial enzyme that responds to apoptotic stimuli by translocating to the nucleus and cleaving the chromatin DNA. The molecular mechanism of EndoG still remains unknown in higher organisms. Here, we determined the crystal structure of mouse EndoG at ∼1.96 Å resolution. The EndoG shows an altered dimeric configuration in which N-terminal region of one subunit interact to the other subunit in dimer. The deletion of this region that is highly conserved in mammalian EndoGs resulted in a monomer with significantly reduced activity suggesting the association of the dimeric arrangement into the nuclease activity. Furthermore, we observed a large conformational change in the loop of the active site groove in EndoG, which corresponds to the DNA binding region. Intriguingly, EndoG dimers are linked by oxidation of the reactive cysteine 110 in this flexible loop to form a long oligomeric chain in the crystal lattice. The structural analysis and ensuing biochemical data suggest that this flexible loop region in the active site is important to the regulation of EndoG nuclease function in mouse.
Collapse
Affiliation(s)
- Kwang-Hyun Park
- Disease Target Structure Research Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB), Daejeon, 305-806, Republic of Korea
| | - Sei Mee Yoon
- Disease Target Structure Research Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB), Daejeon, 305-806, Republic of Korea
| | - Hyung Nam Song
- Disease Target Structure Research Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB), Daejeon, 305-806, Republic of Korea
| | - Joon-Hyuck Yang
- Disease Target Structure Research Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB), Daejeon, 305-806, Republic of Korea; Department of Health Informatics and Management, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Seong Eon Ryu
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, 04673, Republic of Korea.
| | - Eui-Jeon Woo
- Disease Target Structure Research Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB), Daejeon, 305-806, Republic of Korea; Department of Proteome Structural Biology, KRIBB School of Bioscience, University of Science and Technology (UST), Daejeon, 305-333, Republic of Korea.
| |
Collapse
|
6
|
Tan A, Li WS, Verderosa AD, Blakeway LV, D Mubaiwa T, Totsika M, Seib KL. Moraxella catarrhalis NucM is an entry nuclease involved in extracellular DNA and RNA degradation, cell competence and biofilm scaffolding. Sci Rep 2019; 9:2579. [PMID: 30796312 PMCID: PMC6384898 DOI: 10.1038/s41598-019-39374-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/18/2019] [Indexed: 11/10/2022] Open
Abstract
Moraxella catarrhalis is a host-adapted bacterial pathogen that causes otitis media and exacerbations of chronic obstructive pulmonary disease. This study characterises the conserved M. catarrhalis extracellular nuclease, a member of the ββα metal finger family of nucleases, that we have named NucM. NucM shares conserved sequence motifs from the ββα nuclease family, including the DRGH catalytic core and Mg2+ co-ordination site, but otherwise shares little primary sequence identity with other family members, such as the Serratia Nuc and pneumococcal EndA nucleases. NucM is secreted from the cell and digests linear and circular nucleic acid. However, it appears that a proportion of NucM is also associated with the cell membrane and acts as an entry nuclease, facilitating transformation of M. catarrhalis cells. This is the first example of a ββα nuclease in a Gram negative bacteria that acts as an entry nuclease. In addition to its role in competence, NucM affects cell aggregation and biofilm formation by M. catarrhalis, with ΔnucM mutants having increased biofilm biomass. NucM is likely to increase the ability of cells to survive and persist in vivo, increasing the virulence of M. catarrhalis and potentially affecting the behaviour of other pathogens that co-colonise the otorhinolaryngological niche.
Collapse
Affiliation(s)
- Aimee Tan
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4215, Australia
| | - Wing-Sze Li
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4215, Australia
| | - Anthony D Verderosa
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, 4006, Australia
| | - Luke V Blakeway
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4215, Australia
| | - Tsitsi D Mubaiwa
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4215, Australia
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, 4006, Australia
| | - Kate L Seib
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4215, Australia.
| |
Collapse
|
7
|
Zhang Y, Chen T, Zheng W, Li ZH, Ying RF, Tang ZX, Shi LE. Active sites and thermostability of a non-specific nuclease from Yersinia enterocoliticasubsp . palearcticaby site-directed mutagenesis. BIOTECHNOL BIOTEC EQ 2018. [DOI: 10.1080/13102818.2018.1489738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Affiliation(s)
- Yu Zhang
- Department of Biotechnology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, PR China
| | - Tao Chen
- Department of Biotechnology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, PR China
| | - Wei Zheng
- Department of Biotechnology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, PR China
| | - Zhen Hua Li
- Department of Biotechnology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, PR China
| | - Rui-Feng Ying
- Department of Food Engineering, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, Jiangsu, PR China
| | - Zhen-Xing Tang
- Hangzhou Tianlong Group Co. Ltd, Hangzhou, Zhejiang, PR China
| | - Lu-E Shi
- Department of Biotechnology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, PR China
| |
Collapse
|
8
|
Gorelik A, Randriamihaja A, Illes K, Nagar B. Structural basis for nucleotide recognition by the ectoenzyme CD203c. FEBS J 2018; 285:2481-2494. [PMID: 29717535 DOI: 10.1111/febs.14489] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/21/2018] [Accepted: 04/25/2018] [Indexed: 12/11/2022]
Abstract
The ecto-nucleotide pyrophosphatase/phosphodiesterase (NPP) enzyme family modulates purinergic signaling by degrading extracellular nucleotides. CD203c (NPP3, ENPP3) regulates the inflammatory response of basophils via ATP hydrolysis and is a marker for allergen sensitivity on the surface of these cells. Multiple other roles and substrates have also been proposed for this protein. In order to gain insight into its molecular functions, we determined the crystal structure of human NPP3 as well as its complex with an ATP analog. The enzyme exhibits little preference for nucleobase type, and forms specific contacts with the alpha and beta phosphate groups of its ligands. Dimerization of the protein does not affect its catalytic activity. These findings expand our understanding of substrate recognition within the NPP family. DATABASE Structural data are available in the Protein Data Bank under the accession numbers 6C01 (human NPP3) and 6C02 (human NPP3 T205A N594S with AMPCPP).
Collapse
Affiliation(s)
- Alexei Gorelik
- Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
| | - Antsa Randriamihaja
- Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
| | - Katalin Illes
- Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
| | - Bhushan Nagar
- Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
9
|
Bemani P, Mohammadi M, Hakakian A. Anti-ROR1 scFv-EndoG as a Novel Anti-Cancer Therapeutic Drug. Asian Pac J Cancer Prev 2018; 19:97-102. [PMID: 29373898 PMCID: PMC5844643 DOI: 10.22034/apjcp.2018.19.1.97] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aim: Immunotoxins are proteins that consist of an antibody fragment linked to a toxin, used as agents for targeted
therapy of cancers. Although the most potent immunotoxins are made from bacterial and plant toxins, obstacles which
contribute to poor responses are immunogenicity in patients and rapid development of neutralizing antibodies. In the
present study we proposed a new therapeutic immunotoxin for targeted cancer therapy of ROR1 expressing cancers:
an anti ROR1 single chain fragment variable antibody (scFv)-endonuclease G (anti ROR1 scFv-EndoG). Methods:
The three-dimensional structure of anti ROR1 scFv-EndoG protein was modeled and structure validation tools were
employed to confirm the accuracy and reliability of the developed model. In addition, stability and integrity of the
model were assessed by molecular dynamic (MD) simulation. Results: All results suggested the protein model to
be acceptable and of good quality. Conclusions: Anti-ROR1 scFv-EndoG would be expected to bind to the ROR1
extracellular domain by its scFv portion and selectively deliver non-immunogenic human endonuclease G enzyme as
an end-stage apoptosis molecule into ROR1-expressing cancer cells and lead rapidly to apoptosis. We believe that anti
ROR1 and other anti-tumor antigen scFv-EndoG forms may be helpful for cancer therapy.
Collapse
Affiliation(s)
- Peyman Bemani
- Department of Immunology, Shiraz University of Medical Sciences, Shiraz, Iran. ,
| | | | | |
Collapse
|
10
|
Jablonska J, Matelska D, Steczkiewicz K, Ginalski K. Systematic classification of the His-Me finger superfamily. Nucleic Acids Res 2017; 45:11479-11494. [PMID: 29040665 PMCID: PMC5714182 DOI: 10.1093/nar/gkx924] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/29/2017] [Indexed: 02/06/2023] Open
Abstract
The His-Me finger endonucleases, also known as HNH or ββα-metal endonucleases, form a large and diverse protein superfamily. The His-Me finger domain can be found in proteins that play an essential role in cells, including genome maintenance, intron homing, host defense and target offense. Its overall structural compactness and non-specificity make it a perfectly-tailored pathogenic module that participates on both sides of inter- and intra-organismal competition. An extremely low sequence similarity across the superfamily makes it difficult to identify and classify new His-Me fingers. Using state-of-the-art distant homology detection methods, we provide an updated and systematic classification of His-Me finger proteins. In this work, we identified over 100 000 proteins and clustered them into 38 groups, of which three groups are new and cannot be found in any existing public domain database of protein families. Based on an analysis of sequences, structures, domain architectures, and genomic contexts, we provide a careful functional annotation of the poorly characterized members of this superfamily. Our results may inspire further experimental investigations that should address the predicted activity and clarify the potential substrates, to provide more detailed insights into the fundamental biological roles of these proteins.
Collapse
Affiliation(s)
- Jagoda Jablonska
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Dorota Matelska
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Kamil Steczkiewicz
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Krzysztof Ginalski
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| |
Collapse
|
11
|
Oliva C, Sánchez-Murcia PA, Rico E, Bravo A, Menéndez M, Gago F, Jiménez-Ruiz A. Structure-based domain assignment in Leishmania infantum EndoG: characterization of a pH-dependent regulatory switch and a C-terminal extension that largely dictates DNA substrate preferences. Nucleic Acids Res 2017; 45:9030-9045. [PMID: 28911117 PMCID: PMC5587815 DOI: 10.1093/nar/gkx629] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/11/2017] [Indexed: 11/28/2022] Open
Abstract
Mitochondrial endonuclease G from Leishmania infantum (LiEndoG) participates in the degradation of double-stranded DNA (dsDNA) during parasite cell death and is catalytically inactive at a pH of 8.0 or above. The presence, in the primary sequence, of an acidic amino acid-rich insertion exclusive to trypanosomatids and its spatial position in a homology-built model of LiEndoG led us to postulate that this peptide stretch might act as a pH sensor for self-inhibition. We found that a LiEndoG variant lacking residues 145–180 is indeed far more active than its wild-type counterpart at pH values >7.0. In addition, we discovered that (i) LiEndoG exists as a homodimer, (ii) replacement of Ser211 in the active-site SRGH motif with the canonical aspartate from the DRGH motif of other nucleases leads to a catalytically deficient enzyme, (iii) the activity of the S211D variant can be restored upon the concomitant replacement of Ala247 with Arg and (iv) a C-terminal extension is responsible for the observed preferential cleavage of single-stranded DNA (ssDNA) and ssDNA–dsDNA junctions. Taken together, our results support the view that LiEndoG is a multidomain molecular machine whose nuclease activity can be subtly modulated or even abrogated through architectural changes brought about by environmental conditions and interaction with other binding partners.
Collapse
MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution
- Catalytic Domain
- Cloning, Molecular
- DNA Cleavage
- DNA, Protozoan/chemistry
- DNA, Protozoan/genetics
- DNA, Protozoan/metabolism
- DNA, Single-Stranded/chemistry
- DNA, Single-Stranded/genetics
- DNA, Single-Stranded/metabolism
- Endodeoxyribonucleases/chemistry
- Endodeoxyribonucleases/genetics
- Endodeoxyribonucleases/metabolism
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- Hydrogen-Ion Concentration
- Kinetics
- Leishmania infantum/chemistry
- Leishmania infantum/enzymology
- Models, Molecular
- Nucleic Acid Conformation
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Interaction Domains and Motifs
- Protein Multimerization
- Protozoan Proteins/chemistry
- Protozoan Proteins/genetics
- Protozoan Proteins/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Sequence Alignment
- Sequence Deletion
- Sequence Homology, Amino Acid
- Structure-Activity Relationship
- Substrate Specificity
Collapse
Affiliation(s)
- Cristina Oliva
- Departamento de Biología de Sistemas, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
| | - Pedro A. Sánchez-Murcia
- Departamento de Ciencias Biomédicas y “Unidad Asociada IQM-CSIC”, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
| | - Eva Rico
- Departamento de Biología de Sistemas, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
| | - Ana Bravo
- Departamento de Ciencias Biomédicas y “Unidad Asociada IQM-CSIC”, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
| | - Margarita Menéndez
- Instituto de Química Física Rocasolano, Consejo Superior de Investigaciones Científicas (CSIC), E-28006 Madrid, Spain
| | - Federico Gago
- Departamento de Ciencias Biomédicas y “Unidad Asociada IQM-CSIC”, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
- To whom correspondence should be addressed. Tel: +34 918 855 109; Fax: +34 918 854 585; . Correspondence may also be addressed to Federico Gago. Tel: +34 918 854 514; Fax: +34 918 854 591;
| | - Antonio Jiménez-Ruiz
- Departamento de Biología de Sistemas, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
- To whom correspondence should be addressed. Tel: +34 918 855 109; Fax: +34 918 854 585; . Correspondence may also be addressed to Federico Gago. Tel: +34 918 854 514; Fax: +34 918 854 591;
| |
Collapse
|
12
|
A domain in human EXOG converts apoptotic endonuclease to DNA-repair exonuclease. Nat Commun 2017; 8:14959. [PMID: 28466855 PMCID: PMC5418593 DOI: 10.1038/ncomms14959] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 02/16/2017] [Indexed: 11/09/2022] Open
Abstract
Human EXOG (hEXOG) is a 5′-exonuclease that is crucial for mitochondrial DNA repair; the enzyme belongs to a nonspecific nuclease family that includes the apoptotic endonuclease EndoG. Here we report biochemical and structural studies of hEXOG, including structures in its apo form and in a complex with DNA at 1.81 and 1.85 Å resolution, respectively. A Wing domain, absent in other ββα-Me members, suppresses endonuclease activity, but confers on hEXOG a strong 5′-dsDNA exonuclease activity that precisely excises a dinucleotide using an intrinsic ‘tape-measure'. The symmetrical apo hEXOG homodimer becomes asymmetrical upon binding to DNA, providing a structural basis for how substrate DNA bound to one active site allosterically regulates the activity of the other. These properties of hEXOG suggest a pathway for mitochondrial BER that provides an optimal substrate for subsequent gap-filling synthesis by DNA polymerase γ. Human EXOG is crucial for mitochondrial DNA repair. Here the authors present the crystal structures of hEXOG in apo form and as DNA complex and suggest a `tape-measure' activity to generate optimal substrates for mitochondrial base excision repair.
Collapse
|
13
|
Moon AF, Krahn JM, Lu X, Cuneo MJ, Pedersen LC. Structural characterization of the virulence factor Sda1 nuclease from Streptococcus pyogenes. Nucleic Acids Res 2016; 44:3946-57. [PMID: 26969731 PMCID: PMC4856990 DOI: 10.1093/nar/gkw143] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/25/2016] [Indexed: 11/22/2022] Open
Abstract
Infection by Group A Streptococcus pyogenes (GAS) is a leading cause of severe invasive disease in humans, including streptococcal toxic shock syndrome and necrotizing fasciitis. GAS infections lead to nearly 163,000 annual deaths worldwide. Hypervirulent strains of S. pyogenes have evolved a plethora of virulence factors that aid in disease—by promoting bacterial adhesion to host cells, subsequent invasion of deeper tissues and blocking the immune system's attempts to eradicate the infection. Expression and secretion of the extracellular nuclease Sda1 is advantageous for promoting bacterial dissemination throughout the host organism, and evasion of the host's innate immune response. Here we present two crystal structures of Sda1, as well as biochemical studies to address key structural features and surface residues involved in DNA binding and catalysis. In the active site, Asn211 is observed to directly chelate a hydrated divalent metal ion and Arg124, on the putative substrate binding loop, likely stabilizes the transition state during phosphodiester bond cleavage. These structures provide a foundation for rational drug design of small molecule inhibitors to be used in prevention of invasive streptococcal disease.
Collapse
Affiliation(s)
- Andrea F Moon
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Juno M Krahn
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Xun Lu
- Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Matthew J Cuneo
- Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Lars C Pedersen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| |
Collapse
|
14
|
Moon AF, Gaudu P, Pedersen LC. Structural characterization of the virulence factor nuclease A from Streptococcus agalactiae. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:2937-49. [PMID: 25372684 PMCID: PMC4220975 DOI: 10.1107/s1399004714019725] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 09/01/2014] [Indexed: 12/28/2022]
Abstract
The group B pathogen Streptococcus agalactiae commonly populates the human gut and urogenital tract, and is a major cause of infection-based mortality in neonatal infants and in elderly or immunocompromised adults. Nuclease A (GBS_NucA), a secreted DNA/RNA nuclease, serves as a virulence factor for S. agalactiae, facilitating bacterial evasion of the human innate immune response. GBS_NucA efficiently degrades the DNA matrix component of neutrophil extracellular traps (NETs), which attempt to kill and clear invading bacteria during the early stages of infection. In order to better understand the mechanisms of DNA substrate binding and catalysis of GBS_NucA, the high-resolution structure of a catalytically inactive mutant (H148G) was solved by X-ray crystallography. Several mutants on the surface of GBS_NucA which might influence DNA substrate binding and catalysis were generated and evaluated using an imidazole chemical rescue technique. While several of these mutants severely inhibited nuclease activity, two mutants (K146R and Q183A) exhibited significantly increased activity. These structural and biochemical studies have greatly increased our understanding of the mechanism of action of GBS_NucA in bacterial virulence and may serve as a foundation for the structure-based drug design of antibacterial compounds targeted to S. agalactiae.
Collapse
Affiliation(s)
- Andrea F. Moon
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Philippe Gaudu
- INRA, UMR1319 Micalis, Domaine de Vilvert, Jouy-en-Josas, France; AgroParisTech, UMR Micalis, Jouy-en-Josas, France
| | - Lars C. Pedersen
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| |
Collapse
|
15
|
Wang HC, Ho CH, Hsu KC, Yang JM, Wang AHJ. DNA mimic proteins: functions, structures, and bioinformatic analysis. Biochemistry 2014; 53:2865-74. [PMID: 24766129 DOI: 10.1021/bi5002689] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
DNA mimic proteins have DNA-like negative surface charge distributions, and they function by occupying the DNA binding sites of DNA binding proteins to prevent these sites from being accessed by DNA. DNA mimic proteins control the activities of a variety of DNA binding proteins and are involved in a wide range of cellular mechanisms such as chromatin assembly, DNA repair, transcription regulation, and gene recombination. However, the sequences and structures of DNA mimic proteins are diverse, making them difficult to predict by bioinformatic search. To date, only a few DNA mimic proteins have been reported. These DNA mimics were not found by searching for functional motifs in their sequences but were revealed only by structural analysis of their charge distribution. This review highlights the biological roles and structures of 16 reported DNA mimic proteins. We also discuss approaches that might be used to discover new DNA mimic proteins.
Collapse
Affiliation(s)
- Hao-Ching Wang
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University , Taipei 110, Taiwan
| | | | | | | | | |
Collapse
|
16
|
Das A, Chakrabarti J, Ghosh M. Thermodynamics of interfacial changes in a protein–protein complex. ACTA ACUST UNITED AC 2014; 10:437-45. [DOI: 10.1039/c3mb70249a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
17
|
Czene A, Tóth E, Németh E, Otten H, Poulsen JCN, Christensen HEM, Rulíšek L, Nagata K, Larsen S, Gyurcsik B. A new insight into the zinc-dependent DNA-cleavage by the colicin E7 nuclease: a crystallographic and computational study. Metallomics 2014; 6:2090-9. [DOI: 10.1039/c4mt00195h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The crystal structure of a colicin E7 metallonuclease mutant complemented by QM/MM calculations suggests an alternative catalytic mechanism of Zn2+-containing HNH nucleases.
Collapse
Affiliation(s)
- Anikó Czene
- MTA-SZTE Bioinorganic Chemistry Research Group
- H-6720 Szeged, Hungary
| | - Eszter Tóth
- Department of Inorganic and Analytical Chemistry
- University of Szeged
- H-6720 Szeged, Hungary
| | - Eszter Németh
- Department of Inorganic and Analytical Chemistry
- University of Szeged
- H-6720 Szeged, Hungary
| | - Harm Otten
- Department of Chemistry
- University of Copenhagen
- 2100 Copenhagen, Denmark
| | | | | | - Lubomír Rulíšek
- Institute of Organic Chemistry and Biochemistry
- Academy of Sciences of the Czech Republic
- 166 10 Prague 6, Czech Republic
| | - Kyosuke Nagata
- Nagata Special Laboratory
- Faculty of Medicine
- University of Tsukuba
- Tsukuba 305-8575, Japan
| | - Sine Larsen
- Department of Chemistry
- University of Copenhagen
- 2100 Copenhagen, Denmark
| | - Béla Gyurcsik
- MTA-SZTE Bioinorganic Chemistry Research Group
- H-6720 Szeged, Hungary
- Department of Inorganic and Analytical Chemistry
- University of Szeged
- H-6720 Szeged, Hungary
| |
Collapse
|
18
|
Czene A, Németh E, Zóka IG, Jakab-Simon NI, Körtvélyesi T, Nagata K, Christensen HEM, Gyurcsik B. The role of the N-terminal loop in the function of the colicin E7 nuclease domain. J Biol Inorg Chem 2013; 18:309-21. [DOI: 10.1007/s00775-013-0975-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 12/31/2012] [Indexed: 01/10/2023]
|
19
|
Nagamalleswari E, Vasu K, Nagaraja V. Ca(2+) binding to the ExDxD motif regulates the DNA cleavage specificity of a promiscuous endonuclease. Biochemistry 2012; 51:8939-49. [PMID: 23072305 DOI: 10.1021/bi301151y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Most of the restriction endonucleases (REases) are dependent on Mg(2+) for DNA cleavage, and in general, Ca(2+) inhibits their activity. R.KpnI, an HNH active site containing ββα-Me finger nuclease, is an exception. In presence of Ca(2+), the enzyme exhibits high-fidelity DNA cleavage and complete suppression of Mg(2+)-induced promiscuous activity. To elucidate the mechanism of unusual Ca(2+)-mediated activity, we generated alanine variants in the putative Ca(2+) binding motif, E(132)xD(134)xD(136), of the enzyme. Mutants showed decreased levels of DNA cleavage in the presence of Ca(2+). We demonstrate that ExDxD residues are involved in Ca(2+) coordination; however, the invariant His of the catalytic HNH motif acts as a general base for nucleophile activation, and the other two active site residues, D148 and Q175, also participate in Ca(2+)-mediated cleavage. Insertion of a 10-amino acid linker to disrupt the spatial organization of the ExDxD and HNH motifs impairs Ca(2+) binding and affects DNA cleavage by the enzyme. Although ExDxD mutant enzymes retained efficient cleavage at the canonical sites in the presence of Mg(2+), the promiscuous activity was greatly reduced, indicating that the carboxyl residues of the acidic triad play an important role in sequence recognition by the enzyme. Thus, the distinct Ca(2+) binding motif that confers site specific cleavage upon Ca(2+) binding is also critical for the promiscuous activity of the Mg(2+)-bound enzyme, revealing its role in metal ion-mediated modulation of DNA cleavage.
Collapse
Affiliation(s)
- Easa Nagamalleswari
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012, India
| | | | | |
Collapse
|
20
|
Zhang D, de Souza RF, Anantharaman V, Iyer LM, Aravind L. Polymorphic toxin systems: Comprehensive characterization of trafficking modes, processing, mechanisms of action, immunity and ecology using comparative genomics. Biol Direct 2012; 7:18. [PMID: 22731697 PMCID: PMC3482391 DOI: 10.1186/1745-6150-7-18] [Citation(s) in RCA: 358] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 05/31/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Proteinaceous toxins are observed across all levels of inter-organismal and intra-genomic conflicts. These include recently discovered prokaryotic polymorphic toxin systems implicated in intra-specific conflicts. They are characterized by a remarkable diversity of C-terminal toxin domains generated by recombination with standalone toxin-coding cassettes. Prior analysis revealed a striking diversity of nuclease and deaminase domains among the toxin modules. We systematically investigated polymorphic toxin systems using comparative genomics, sequence and structure analysis. RESULTS Polymorphic toxin systems are distributed across all major bacterial lineages and are delivered by at least eight distinct secretory systems. In addition to type-II, these include type-V, VI, VII (ESX), and the poorly characterized "Photorhabdus virulence cassettes (PVC)", PrsW-dependent and MuF phage-capsid-like systems. We present evidence that trafficking of these toxins is often accompanied by autoproteolytic processing catalyzed by HINT, ZU5, PrsW, caspase-like, papain-like, and a novel metallopeptidase associated with the PVC system. We identified over 150 distinct toxin domains in these systems. These span an extraordinary catalytic spectrum to include 23 distinct clades of peptidases, numerous previously unrecognized versions of nucleases and deaminases, ADP-ribosyltransferases, ADP ribosyl cyclases, RelA/SpoT-like nucleotidyltransferases, glycosyltranferases and other enzymes predicted to modify lipids and carbohydrates, and a pore-forming toxin domain. Several of these toxin domains are shared with host-directed effectors of pathogenic bacteria. Over 90 families of immunity proteins might neutralize anywhere between a single to at least 27 distinct types of toxin domains. In some organisms multiple tandem immunity genes or immunity protein domains are organized into polyimmunity loci or polyimmunity proteins. Gene-neighborhood-analysis of polymorphic toxin systems predicts the presence of novel trafficking-related components, and also the organizational logic that allows toxin diversification through recombination. Domain architecture and protein-length analysis revealed that these toxins might be deployed as secreted factors, through directed injection, or via inter-cellular contact facilitated by filamentous structures formed by RHS/YD, filamentous hemagglutinin and other repeats. Phyletic pattern and life-style analysis indicate that polymorphic toxins and polyimmunity loci participate in cooperative behavior and facultative 'cheating' in several ecosystems such as the human oral cavity and soil. Multiple domains from these systems have also been repeatedly transferred to eukaryotes and their viruses, such as the nucleo-cytoplasmic large DNA viruses. CONCLUSIONS Along with a comprehensive inventory of toxins and immunity proteins, we present several testable predictions regarding active sites and catalytic mechanisms of toxins, their processing and trafficking and their role in intra-specific and inter-specific interactions between bacteria. These systems provide insights regarding the emergence of key systems at different points in eukaryotic evolution, such as ADP ribosylation, interaction of myosin VI with cargo proteins, mediation of apoptosis, hyphal heteroincompatibility, hedgehog signaling, arthropod toxins, cell-cell interaction molecules like teneurins and different signaling messengers.
Collapse
Affiliation(s)
- Dapeng Zhang
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | | | | | | | | |
Collapse
|
21
|
Zhukhlistova NE, Balaev VV, Lyashenko AV, Lashkov AA. Structural aspects of catalytic mechanisms of endonucleases and their binding to nucleic acids. CRYSTALLOGR REP+ 2012. [DOI: 10.1134/s1063774512030236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
22
|
Lin JLJ, Nakagawa A, Lin CL, Hsiao YY, Yang WZ, Wang YT, Doudeva LG, Skeen-Gaar RR, Xue D, Yuan HS. Structural insights into apoptotic DNA degradation by CED-3 protease suppressor-6 (CPS-6) from Caenorhabditis elegans. J Biol Chem 2012; 287:7110-20. [PMID: 22223640 PMCID: PMC3293555 DOI: 10.1074/jbc.m111.316075] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 12/30/2011] [Indexed: 11/06/2022] Open
Abstract
Endonuclease G (EndoG) is a mitochondrial protein that traverses to the nucleus and participates in chromosomal DNA degradation during apoptosis in yeast, worms, flies, and mammals. However, it remains unclear how EndoG binds and digests DNA. Here we show that the Caenorhabditis elegans CPS-6, a homolog of EndoG, is a homodimeric Mg(2+)-dependent nuclease, binding preferentially to G-tract DNA in the optimum low salt buffer at pH 7. The crystal structure of CPS-6 was determined at 1.8 Å resolution, revealing a mixed αβ topology with the two ββα-metal finger nuclease motifs located distantly at the two sides of the dimeric enzyme. A structural model of the CPS-6-DNA complex suggested a positively charged DNA-binding groove near the Mg(2+)-bound active site. Mutations of four aromatic and basic residues: Phe(122), Arg(146), Arg(156), and Phe(166), in the protein-DNA interface significantly reduced the DNA binding and cleavage activity of CPS-6, confirming that these residues are critical for CPS-6-DNA interactions. In vivo transformation rescue experiments further showed that the reduced DNase activity of CPS-6 mutants was positively correlated with its diminished cell killing activity in C. elegans. Taken together, these biochemical, structural, mutagenesis, and in vivo data reveal a molecular basis of how CPS-6 binds and hydrolyzes DNA to promote cell death.
Collapse
Affiliation(s)
- Jason L. J. Lin
- From the Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Akihisa Nakagawa
- the Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Chia Liang Lin
- From the Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
- the Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu 30013, Taiwan, and
| | - Yu-Yuan Hsiao
- From the Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Wei-Zen Yang
- From the Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Ting Wang
- From the Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Lyudmila G. Doudeva
- From the Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Riley Robert Skeen-Gaar
- the Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Ding Xue
- the Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Hanna S. Yuan
- From the Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
- the Graduate Institute of Biochemistry and Molecular Biology, National Taiwan University, Taipei 10617, Taiwan
| |
Collapse
|
23
|
Nishimasu H, Ishitani R, Aoki J, Nureki O. A 3D view of autotaxin. Trends Pharmacol Sci 2012; 33:138-45. [DOI: 10.1016/j.tips.2011.12.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 12/16/2011] [Accepted: 12/23/2011] [Indexed: 12/26/2022]
|
24
|
Towards artificial metallonucleases for gene therapy: recent advances and new perspectives. Future Med Chem 2011; 3:1935-66. [DOI: 10.4155/fmc.11.139] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The process of DNA targeting or repair of mutated genes within the cell, induced by specifically positioned double-strand cleavage of DNA near the mutated sequence, can be applied for gene therapy of monogenic diseases. For this purpose, highly specific artificial metallonucleases are developed. They are expected to be important future tools of modern genetics. The present state of art and strategies of research are summarized, including protein engineering and artificial ‘chemical’ nucleases. From the results, we learn about the basic role of the metal ions and the various ligands, and about the DNA binding and cleavage mechanism. The results collected provide useful guidance for engineering highly controlled enzymes for use in gene therapy.
Collapse
|
25
|
Bueren-Calabuig JA, Coderch C, Rico E, Jiménez-Ruiz A, Gago F. Mechanistic insight into the catalytic activity of ββα-metallonucleases from computer simulations: Vibrio vulnificus periplasmic nuclease as a test case. Chembiochem 2011; 12:2615-22. [PMID: 22114054 DOI: 10.1002/cbic.201100485] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Indexed: 11/08/2022]
Abstract
Using information from wild-type and mutant Vibrio vulnificus nuclease (Vvn) and I-PpoI homing endonuclease co-crystallized with different oligodeoxynucleotides, we have built the complex of Vvn with a DNA octamer and carried out a series of simulations to dissect the catalytic mechanism of this metallonuclease in a stepwise fashion. The distinct roles played in the reaction by individual active site residues, the metal cation and water molecules have been clarified by using a combination of classical molecular dynamics simulations and quantum mechanical calculations. Our results strongly support the most parsimonious catalytic mechanism, namely one in which a single water molecule from bulk solvent is used to cleave the phosphodiester bond and protonate the 3'-hydroxylate leaving group.
Collapse
Affiliation(s)
- Juan A Bueren-Calabuig
- Department of Pharmacology, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain
| | | | | | | | | |
Collapse
|
26
|
Korczynska JE, Turkenburg JP, Taylor EJ. The structural characterization of a prophage-encoded extracellular DNase from Streptococcus pyogenes. Nucleic Acids Res 2011; 40:928-38. [PMID: 21948797 PMCID: PMC3258162 DOI: 10.1093/nar/gkr789] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The pathogenic bacterium Group A Streptococcus pyogenes produces several extracellular DNases that have been shown to facilitate invasive infection by evading the human host immune system. DNases degrade the chromatin in neutrophil extracellular traps, enabling the bacterium to evade neutrophil capture. Spd1 is a type I, nonspecific ββα/metal-dependent nuclease from Streptococcus pyogenes, which is encoded by the SF370.1 prophage and is likely to be expressed as a result of prophage induction. We present here the X-ray structure of this DNase in the wild-type and Asn145Ala mutant form. Through structural and sequence alignments as well as mutagenesis studies, we have identified the key residues His121, Asn145 and Glu164, which are crucial for Spd1 nucleolytic activity and shown the active site constellation. Our wild-type structure alludes to the possibility of a catalytically blocked dimeric form of the protein. We have investigated the multimeric nature of Spd1 using size-exclusion chromatography with multi-angle light scattering (SEC-MALLS) in the presence and absence of the divalent metal ion Mg(2+), which suggests that Spd1 exists in a monomeric form in solution.
Collapse
Affiliation(s)
- Justyna E Korczynska
- Department of Chemistry, Structural Biology Laboratory, The University of York, YO10 5YW, UK
| | | | | |
Collapse
|
27
|
Vasu K, Saravanan M, Nagaraja V. Endonuclease active site plasticity allows DNA cleavage with diverse alkaline Earth and transition metal ions. ACS Chem Biol 2011; 6:934-42. [PMID: 21736285 DOI: 10.1021/cb200107y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A majority of enzymes show a high degree of specificity toward a particular metal ion in their catalytic reaction. However, Type II restriction endonuclease (REase) R.KpnI, which is the first member of the HNH superfamily of REases, exhibits extraordinary diversity in metal ion dependent DNA cleavage. Several alkaline earth and transition group metal ions induce high fidelity and promiscuous cleavage or inhibition depending upon their concentration. The metal ions having different ionic radii and co-ordination geometries readily replace each other from the enzyme's active site, revealing its plasticity. Ability of R.KpnI to cleave DNA with both alkaline earth and transition group metal ions having varied ionic radii could imply utilization of different catalytic site(s). However, mutation of the invariant His residue of the HNH motif caused abolition of the enzyme activity with all of the cofactors, indicating that the enzyme follows a single metal ion catalytic mechanism for DNA cleavage. Indispensability of His in nucleophile activation together with broad cofactor tolerance of the enzyme indicates electrostatic stabilization function of metal ions during catalysis. Nevertheless, a second metal ion is recruited at higher concentrations to either induce promiscuity or inhibit the DNA cleavage. Regulation of the endonuclease activity and fidelity by a second metal ion binding is a unique feature of R.KpnI among REases and HNH nucleases. The active site plasticity of R.KpnI opens up avenues for redesigning cofactor specificities and generation of mutants specific to a particular metal ion.
Collapse
Affiliation(s)
- Kommireddy Vasu
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012, India
| | - Matheshwaran Saravanan
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012, India
| | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012, India
- Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560 064, India
| |
Collapse
|
28
|
Zhang D, Iyer LM, Aravind L. A novel immunity system for bacterial nucleic acid degrading toxins and its recruitment in various eukaryotic and DNA viral systems. Nucleic Acids Res 2011; 39:4532-52. [PMID: 21306995 PMCID: PMC3113570 DOI: 10.1093/nar/gkr036] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The use of nucleases as toxins for defense, offense or addiction of selfish elements is widely encountered across all life forms. Using sensitive sequence profile analysis methods, we characterize a novel superfamily (the SUKH superfamily) that unites a diverse group of proteins including Smi1/Knr4, PGs2, FBXO3, SKIP16, Syd, herpesviral US22, IRS1 and TRS1, and their bacterial homologs. Using contextual analysis we present evidence that the bacterial members of this superfamily are potential immunity proteins for a variety of toxin systems that also include the recently characterized contact-dependent inhibition (CDI) systems of proteobacteria. By analyzing the toxin proteins encoded in the neighborhood of the SUKH superfamily we predict that they possess domains belonging to diverse nuclease and nucleic acid deaminase families. These include at least eight distinct types of DNases belonging to HNH/EndoVII- and restriction endonuclease-fold, and RNases of the EndoU-like and colicin E3-like cytotoxic RNases-folds. The N-terminal domains of these toxins indicate that they are extruded by several distinct secretory mechanisms such as the two-partner system (shared with the CDI systems) in proteobacteria, ESAT-6/WXG-like ATP-dependent secretory systems in Gram-positive bacteria and the conventional Sec-dependent system in several bacterial lineages. The hedgehog-intein domain might also release a subset of toxic nuclease domains through auto-proteolytic action. Unlike classical colicin-like nuclease toxins, the overwhelming majority of toxin systems with the SUKH superfamily is chromosomally encoded and appears to have diversified through a recombination process combining different C-terminal nuclease domains to N-terminal secretion-related domains. Across the bacterial superkingdom these systems might participate in discriminating `self’ or kin from `non-self’ or non-kin strains. Using structural analysis we demonstrate that the SUKH domain possesses a versatile scaffold that can be used to bind a wide range of protein partners. In eukaryotes it appears to have been recruited as an adaptor to regulate modification of proteins by ubiquitination or polyglutamylation. Similarly, another widespread immunity protein from these toxin systems, namely the suppressor of fused (SuFu) superfamily has been recruited for comparable roles in eukaryotes. In animal DNA viruses, such as herpesviruses, poxviruses, iridoviruses and adenoviruses, the ability of the SUKH domain to bind diverse targets has been deployed to counter diverse anti-viral responses by interacting with specific host proteins.
Collapse
Affiliation(s)
- Dapeng Zhang
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | | | | |
Collapse
|
29
|
Nishimasu H, Okudaira S, Hama K, Mihara E, Dohmae N, Inoue A, Ishitani R, Takagi J, Aoki J, Nureki O. Crystal structure of autotaxin and insight into GPCR activation by lipid mediators. Nat Struct Mol Biol 2011; 18:205-12. [PMID: 21240269 DOI: 10.1038/nsmb.1998] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2010] [Accepted: 11/19/2010] [Indexed: 01/08/2023]
Abstract
Autotaxin (ATX, also known as Enpp2) is a secreted lysophospholipase D that hydrolyzes lysophosphatidylcholine to generate lysophosphatidic acid (LPA), a lipid mediator that activates G protein-coupled receptors to evoke various cellular responses. Here, we report the crystal structures of mouse ATX alone and in complex with LPAs with different acyl-chain lengths and saturations. These structures reveal that the multidomain architecture helps to maintain the structural rigidity of the lipid-binding pocket, which accommodates the respective LPA molecules in distinct conformations. They indicate that a loop region in the catalytic domain is a major determinant for the substrate specificity of the Enpp family enzymes. Furthermore, along with biochemical and biological data, these structures suggest that the produced LPAs are delivered from the active site to cognate G protein-coupled receptors through a hydrophobic channel.
Collapse
Affiliation(s)
- Hiroshi Nishimasu
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Hausmann J, Kamtekar S, Christodoulou E, Day JE, Wu T, Fulkerson Z, Albers HMHG, van Meeteren LA, Houben AJS, van Zeijl L, Jansen S, Andries M, Hall T, Pegg LE, Benson TE, Kasiem M, Harlos K, Kooi CWV, Smyth SS, Ovaa H, Bollen M, Morris AJ, Moolenaar WH, Perrakis A. Structural basis of substrate discrimination and integrin binding by autotaxin. Nat Struct Mol Biol 2011; 18:198-204. [PMID: 21240271 PMCID: PMC3064516 DOI: 10.1038/nsmb.1980] [Citation(s) in RCA: 218] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 11/08/2010] [Indexed: 12/11/2022]
Abstract
Autotaxin (ATX) or ecto-nucleotide pyrophosphatase/phosphodiesterase-2 (ENPP2) is a secreted lysophospholipase D that generates the lipid mediator lysophosphatidic acid (LPA), a mitogen and chemo-attractant for many cell types. ATX-LPA signaling has roles in various pathologies including tumour progression and inflammation. However, the molecular basis of substrate recognition and catalysis, and the mechanism of interaction with target cells, has been elusive. Here we present the crystal structure of ATX, alone and in complex with a small-molecule inhibitor. We identify a hydrophobic lipid-binding pocket and map key residues required for catalysis and selection between nucleotide and phospholipid substrates. We show that ATX interacts with cell-surface integrins via its N-terminal somatomedin-B-like domains, using an atypical mechanism. Our results define determinants of substrate discrimination by the ENPP family, suggest how ATX promotes localized LPA signaling, and enable new approaches to target ATX with small-molecule therapeutics.
Collapse
Affiliation(s)
- Jens Hausmann
- Division of Biochemistry, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Moon AF, Midon M, Meiss G, Pingoud A, London RE, Pedersen LC. Structural insights into catalytic and substrate binding mechanisms of the strategic EndA nuclease from Streptococcus pneumoniae. Nucleic Acids Res 2010; 39:2943-53. [PMID: 21113026 PMCID: PMC3074123 DOI: 10.1093/nar/gkq1152] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
EndA is a sequence non-specific endonuclease that serves as a virulence factor during Streptococcus pneumoniae infection. Expression of EndA provides a strategy for evasion of the host's neutrophil extracellular traps, digesting the DNA scaffold structure and allowing further invasion by S. pneumoniae. To define mechanisms of catalysis and substrate binding, we solved the structure of EndA at 1.75 Å resolution. The EndA structure reveals a DRGH (Asp-Arg-Gly-His) motif-containing ββα-metal finger catalytic core augmented by an interesting ‘finger-loop’ interruption of the active site α-helix. Subsequently, we delineated DNA binding versus catalytic functionality using structure-based alanine substitution mutagenesis. Three mutants, H154A, Q186A and Q192A, exhibited decreased nuclease activity that appears to be independent of substrate binding. Glu205 was found to be crucial for catalysis, while residues Arg127/Lys128 and Arg209/Lys210 contribute to substrate binding. The results presented here provide the molecular foundation for development of specific antibiotic inhibitors for EndA.
Collapse
Affiliation(s)
- Andrea F Moon
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
| | | | | | | | | | | |
Collapse
|
32
|
Midon M, Schäfer P, Pingoud A, Ghosh M, Moon AF, Cuneo MJ, London RE, Meiss G. Mutational and biochemical analysis of the DNA-entry nuclease EndA from Streptococcus pneumoniae. Nucleic Acids Res 2010; 39:623-34. [PMID: 20846957 PMCID: PMC3025545 DOI: 10.1093/nar/gkq802] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
EndA is a membrane-attached surface-exposed DNA-entry nuclease previously known to be required for genetic transformation of Streptococcus pneumoniae. More recent studies have shown that the enzyme also plays an important role during the establishment of invasive infections by degrading extracellular chromatin in the form of neutrophil extracellular traps (NETs), enabling streptococci to overcome the innate immune system in mammals. As a virulence factor, EndA has become an interesting target for future drug design. Here we present the first mutational and biochemical analysis of recombinant forms of EndA produced either in a cell-free expression system or in Escherichia coli. We identify His160 and Asn191 to be essential for catalysis and Asn182 to be required for stability of EndA. The role of His160 as the putative general base in the catalytic mechanism is supported by chemical rescue of the H160A variant of EndA with imidazole added in excess. Our study paves the way for the identification and development of protein or low-molecular-weight inhibitors for EndA in future high-throughput screening assays.
Collapse
Affiliation(s)
- Marika Midon
- Institute of Biochemistry, Justus-Liebig-University Giessen, Giessen, Germany
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Loll B, Gebhardt M, Wahle E, Meinhart A. Crystal structure of the EndoG/EndoGI complex: mechanism of EndoG inhibition. Nucleic Acids Res 2010; 37:7312-20. [PMID: 19783821 PMCID: PMC2790893 DOI: 10.1093/nar/gkp770] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
EndoG is a ubiquitous nuclease that is translocated into the nucleus during apoptosis to participate in DNA degradation. The enzyme cleaves double- and single-stranded DNA and RNA. Related nucleases are found in eukaryotes and prokaryotes, which have evolved sophisticated mechanisms for genome protection against self-antagonizing nuclease activity. Common mechanisms of inhibition are secretion, sequestration into a separate cellular compartment or by binding to protein inhibitors. Although EndoG is silenced by compartmentalization into the mitochondrial intermembrane space, a nucleus-localized protein inhibitor protects cellular polynucleotides from degradation by stray EndoG under non-apoptotic conditions in Drosophila. Here, we report the first three-dimensional structure of EndoG in complex with its inhibitor EndoGI. Although the mechanism of inhibition is reminiscent of bacterial protein inhibitors, EndoGI has evolved independently from a generic protein-protein interaction module. EndoGI is a two-domain protein that binds the active sites of two monomers of EndoG, with EndoG being sandwiched between EndoGI. Since the amino acid sequences of eukaryotic EndoG homologues are highly conserved, this model is valid for eukaryotic dimeric EndoG in general. The structure indicates that the two active sites of EndoG occupy the most remote spatial position possible at the molecular surface and a concerted substrate processing is unlikely.
Collapse
Affiliation(s)
- Bernhard Loll
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | | | | | | |
Collapse
|
34
|
Yoon SM, Song HN, Yang JH, Lim MY, Chung YJ, Ryu SE, Woo EJ. Purification, crystallization and data collection of the apoptotic nuclease endonuclease G. Acta Crystallogr Sect F Struct Biol Cryst Commun 2009; 65:504-7. [PMID: 19407388 PMCID: PMC2675596 DOI: 10.1107/s1744309109013335] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Accepted: 04/08/2009] [Indexed: 11/10/2022]
Abstract
Endonuclease G (EndoG) is a mitochondrial enzyme that responds to apoptotic stimuli by translocating to the nucleus and cleaving chromosomal DNA. EndoG is the main apoptotic endonuclease in the caspase-independent pathway. Mouse EndoG without the mitochondrial localization signal (amino-acid residues 1-43) was successfully overexpressed, purified and crystallized using a microbatch method under oil. The initial crystal (type I) was grown in the presence of the detergent CTAB and diffracted to 2.8 A resolution, with unit-cell parameters a = 72.20, b = 81.88, c = 88.66 A, beta = 97.59 degrees in a monoclinic space group. The crystal contained two monomers in the asymmetric unit, with a predicted solvent content of 46.6%. Subsequent mutation of Cys110 improved the stability of the protein significantly and produced further crystals of types II, III and IV with space groups C2, P4(1)2(1)2 (or P4(3)2(1)2) and P2(1)2(1)2(1), respectively, in various conditions. This suggests the critical involvement of this conserved cysteine residue in the crystallization process.
Collapse
Affiliation(s)
- Sei Mee Yoon
- Medical Proteomic Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 306-333, Republic of Korea
- Department of Biochemistry, Chungbuk National University, Cheongju 361-763, Republic of Korea
| | - Hyung Nam Song
- Medical Proteomic Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 306-333, Republic of Korea
| | - Jun Hyuk Yang
- Medical Proteomic Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 306-333, Republic of Korea
| | - Mi Yeon Lim
- Medical Proteomic Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 306-333, Republic of Korea
| | - Yong Je Chung
- Department of Biochemistry, Chungbuk National University, Cheongju 361-763, Republic of Korea
| | - Seong Eon Ryu
- Medical Proteomic Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 306-333, Republic of Korea
- Systemic Proteomes Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 306-333, Republic of Korea
| | - Eui Jeon Woo
- Medical Proteomic Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 306-333, Republic of Korea
| |
Collapse
|
35
|
Sokolowska M, Czapinska H, Bochtler M. Crystal structure of the beta beta alpha-Me type II restriction endonuclease Hpy99I with target DNA. Nucleic Acids Res 2009; 37:3799-810. [PMID: 19380375 PMCID: PMC2699513 DOI: 10.1093/nar/gkp228] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The ββα-Me restriction endonuclease (REase) Hpy99I recognizes the CGWCG target sequence and cleaves it with unusual stagger (five nucleotide 5′-recessed ends). Here we present the crystal structure of the specific complex of the dimeric enzyme with DNA. The Hpy99I protomer consists of an antiparallel β-barrel and two β4α2 repeats. Each repeat coordinates a structural zinc ion with four cysteine thiolates in two CXXC motifs. The ββα-Me region of the second β4α2 repeat holds the catalytic metal ion (or its sodium surrogate) via Asp148 and Asn165 and activates a water molecule with the general base His149. In the specific complex, Hpy99I forms a ring-like structure around the DNA that contacts DNA bases on the major and minor groove sides via the first and second β4α2 repeats, respectively. Hpy99I interacts with the central base pair of the recognition sequence only on the minor groove side, where A:T resembles T:A and G:C is similar to C:G. The Hpy99I–DNA co-crystal structure provides the first detailed illustration of the ββα-Me site in REases and complements structural information on the use of this active site motif in other groups of endonucleases such as homing endonucleases (e.g. I-PpoI) and Holliday junction resolvases (e.g. T4 endonuclease VII).
Collapse
Affiliation(s)
- Monika Sokolowska
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland
| | | | | |
Collapse
|
36
|
Wu SL, Li CC, Chen JC, Chen YJ, Lin CT, Ho TY, Hsiang CY. Mutagenesis identifies the critical amino acid residues of human endonuclease G involved in catalysis, magnesium coordination, and substrate specificity. J Biomed Sci 2009; 16:6. [PMID: 19272175 PMCID: PMC2653514 DOI: 10.1186/1423-0127-16-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2008] [Accepted: 01/15/2009] [Indexed: 11/29/2022] Open
Abstract
Background Endonuclease G (EndoG), a member of DNA/RNA nonspecific ββα-Me-finger nucleases, is involved in apoptosis and normal cellular proliferation. In this study, we analyzed the critical amino acid residues of EndoG and proposed the catalytic mechanism of EndoG. Methods To identify the critical amino acid residues of human EndoG, we replaced the conserved histidine, asparagine, and arginine residues with alanine. The catalytic efficacies of Escherichia coli-expressed EndoG variants were further analyzed by kinetic studies. Results Diethyl pyrocarbonate modification assay revealed that histidine residues were involved in EndoG activity. His-141, Asn-163, and Asn-172 in the H-N-H motif of EndoG were critical for catalysis and substrate specificity. H141A mutant required a higher magnesium concentration to achieve its activity, suggesting the unique role of His-141 in both catalysis and magnesium coordination. Furthermore, an additional catalytic residue (Asn-251) and an additional metal ion binding site (Glu-271) of human EndoG were identified. Conclusion Based on the mutational analysis and homology modeling, we proposed that human EndoG shared a similar catalytic mechanism with nuclease A from Anabaena.
Collapse
Affiliation(s)
- Shih-Lu Wu
- Department of Biochemistry, China Medical University, Taichung 40402, Taiwan.
| | | | | | | | | | | | | |
Collapse
|
37
|
Rico E, Alzate JF, Arias AA, Moreno D, Clos J, Gago F, Moreno I, Domínguez M, Jiménez-Ruiz A. Leishmania infantum expresses a mitochondrial nuclease homologous to EndoG that migrates to the nucleus in response to an apoptotic stimulus. Mol Biochem Parasitol 2009; 163:28-38. [DOI: 10.1016/j.molbiopara.2008.09.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 09/08/2008] [Accepted: 09/12/2008] [Indexed: 10/21/2022]
|
38
|
Song Q, Zhang X. Characterization of a novel non-specific nuclease from thermophilic bacteriophage GBSV1. BMC Biotechnol 2008; 8:43. [PMID: 18439318 PMCID: PMC2390534 DOI: 10.1186/1472-6750-8-43] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Accepted: 04/28/2008] [Indexed: 11/25/2022] Open
Abstract
Background Thermostable enzymes from thermophiles have attracted extensive studies. In this investigation, a nuclease-encoding gene (designated as GBSV1-NSN) was obtained from a thermophilic bacteriophage GBSV1 for the first time. Results After recombinant expression in Escherichia coli, the purified GBSV1-NSN exhibited non-specific nuclease activity, being able to degrade various nucleic acids, including RNA, single-stranded DNA and double-stranded DNA that was circular or linear. Based on sequence analysis, the nuclease shared no homology with any known nucleases, suggesting that it was a novel nuclease. The characterization of the recombinant GBSV1-NSN showed that its optimal temperature and pH were 60°C and 7.5, respectively. The results indicated that the enzymatic activity was inhibited by enzyme inhibitors or detergents, such as ethylene diamine tetraacetic acid, citrate, dithiothreitol, β-mercaptoethanol, guanidine hydrochloride, urea and SDS. In contrast, the nuclease activity was enhanced by TritonX-100, Tween-20 or chaps to approximately 124.5% – 141.6%. The Km of GBSV1-NSN nuclease was 231, 61 and 92 μM, while its kcat was 1278, 241 and 300 s-1 for the cleavage of dsDNA, ssDNA and RNA, respectively. Conclusion Our study, therefore, presented a novel thermostable non-specific nuclease from thermophilic bacteriophage and its overexpression and purification for scientific research and applications.
Collapse
Affiliation(s)
- Qing Song
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, The People's Republic of China.
| | | |
Collapse
|
39
|
Dupureur CM. Roles of metal ions in nucleases. Curr Opin Chem Biol 2008; 12:250-5. [PMID: 18261473 DOI: 10.1016/j.cbpa.2008.01.012] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Accepted: 01/09/2008] [Indexed: 10/22/2022]
Abstract
The hydrolysis of phosphodiester bonds by metallonucleases is crucial to most aspects of nucleic acid processing. In recent years, studies of the classical restriction endonucleases have given way to the characterization of metallonucleases with widely divergent active site motifs. These developments fuel debates regarding the roles of metal ions in these enzymes. It is fortuitous that the current literature also includes the increased application of a variety of computational techniques to test the roles of metal ions in nucleic acid hydrolysis by these systems. This includes recent proposals and indirect evidence that these enzymes utilize metal ion movement in these reactions.
Collapse
Affiliation(s)
- Cynthia M Dupureur
- Department of Chemistry & Biochemistry and the Center for Nanoscience, University of Missouri-St. Louis, MC 27, One University Boulevard, St. Louis, MO 63121, United States.
| |
Collapse
|
40
|
Cymerman IA, Chung I, Beckmann BM, Bujnicki JM, Meiss G. EXOG, a novel paralog of Endonuclease G in higher eukaryotes. Nucleic Acids Res 2008; 36:1369-79. [PMID: 18187503 PMCID: PMC2275078 DOI: 10.1093/nar/gkm1169] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Evolutionary conserved mitochondrial nucleases are involved in programmed cell death and normal cell proliferation in lower and higher eukaryotes. The endo/exonuclease Nuc1p, also termed ‘yeast Endonuclease G (EndoG)’, is a member of this class of enzymes that differs from mammalian homologs by the presence of a 5′–3′ exonuclease activity in addition to its broad spectrum endonuclease activity. However, this exonuclease activity is thought to be essential for a function of the yeast enzyme in DNA recombination and repair. Here we show that higher eukaryotes in addition to EndoG contain its paralog ‘EXOG’, a novel EndoG-like mitochondrial endo/exonuclease. We find that during metazoan evolution duplication of an ancestral nuclease gene obviously generated the paralogous EndoG- and EXOG-protein subfamilies in higher eukaryotes, thereby maintaining the full endo/exonuclease activity found in mitochondria of lower eukaryotes. We demonstrate that human EXOG is a dimeric mitochondrial enzyme that displays 5′–3′ exonuclease activity and further differs from EndoG in substrate specificity. We hypothesize that in higher eukaryotes the complementary enzymatic activities of EndoG and EXOG probably together account for both, the lethal and vital functions of conserved mitochondrial endo/exonucleases.
Collapse
Affiliation(s)
- Iwona A Cymerman
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland
| | | | | | | | | |
Collapse
|
41
|
Ghosh M, Meiss G, Pingoud A, London RE, Pedersen LC. The nuclease a-inhibitor complex is characterized by a novel metal ion bridge. J Biol Chem 2007; 282:5682-90. [PMID: 17138564 PMCID: PMC2072808 DOI: 10.1074/jbc.m605986200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nonspecific, extracellular nucleases have received enhanced attention recently as a consequence of the critical role that these enzymes can play in infectivity by overcoming the host neutrophil defense system. The activity of the cyanobacterial nuclease NucA, a member of the betabetaalpha Me superfamily, is controlled by the specific nuclease inhibitor, NuiA. Here we report the 2.3-A resolution crystal structure of the NucA-NuiA complex, showing that NucA inhibition by NuiA involves an unusual divalent metal ion bridge that connects the nuclease with its inhibitor. The C-terminal Thr-135(NuiA) hydroxyl oxygen is directly coordinated with the catalytic Mg(2+) of the nuclease active site, and Glu-24(NuiA) also extends into the active site, mimicking the charge of a scissile phosphate. NuiA residues Asp-75 and Trp-76 form a second interaction site, contributing to the strength and specificity of the interaction. The crystallographically defined interface is shown to be consistent with results of studies using site-directed NuiA mutants. This mode of inhibition differs dramatically from the exosite mechanism of inhibition seen with the DNase colicins E7/E9 and from other nuclease-inhibitor complexes that have been studied. The structure of this complex provides valuable insights for the development of inhibitors for related nonspecific nucleases that share the DRGH active site motif such as the Streptococcus pneumoniae nuclease EndA, which mediates infectivity of this pathogen, and mitochondrial EndoG, which is involved in recombination and apoptosis.
Collapse
Affiliation(s)
- Mahua Ghosh
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Gregor Meiss
- Institut für Biochemie (FB 08), Justus-Liebig-Universität, Heinrich-Buff-Ring 58, D-35392, Giessen, Germany
| | - Alfred Pingoud
- Institut für Biochemie (FB 08), Justus-Liebig-Universität, Heinrich-Buff-Ring 58, D-35392, Giessen, Germany
| | - Robert E. London
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Lars C. Pedersen
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| |
Collapse
|