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Hobble HV, Schaner Tooley CE. Intrafamily heterooligomerization as an emerging mechanism of methyltransferase regulation. Epigenetics Chromatin 2024; 17:5. [PMID: 38429855 PMCID: PMC10908127 DOI: 10.1186/s13072-024-00530-0] [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: 12/15/2023] [Accepted: 02/10/2024] [Indexed: 03/03/2024] Open
Abstract
Protein and nucleic acid methylation are important biochemical modifications. In addition to their well-established roles in gene regulation, they also regulate cell signaling, metabolism, and translation. Despite this high biological relevance, little is known about the general regulation of methyltransferase function. Methyltransferases are divided into superfamilies based on structural similarities and further classified into smaller families based on sequence/domain/target similarity. While members within superfamilies differ in substrate specificity, their structurally similar active sites indicate a potential for shared modes of regulation. Growing evidence from one superfamily suggests a common regulatory mode may be through heterooligomerization with other family members. Here, we describe examples of methyltransferase regulation through intrafamily heterooligomerization and discuss how this can be exploited for therapeutic use.
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Affiliation(s)
- Haley V Hobble
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Christine E Schaner Tooley
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA.
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2
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Bower EKM, Cooper LP, Roberts GA, White JH, Luyten Y, Morgan RD, Dryden DTF. A model for the evolution of prokaryotic DNA restriction-modification systems based upon the structural malleability of Type I restriction-modification enzymes. Nucleic Acids Res 2019; 46:9067-9080. [PMID: 30165537 PMCID: PMC6158711 DOI: 10.1093/nar/gky760] [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: 10/05/2017] [Accepted: 08/21/2018] [Indexed: 12/28/2022] Open
Abstract
Restriction Modification (RM) systems prevent the invasion of foreign genetic material into bacterial cells by restriction and protect the host's genetic material by methylation. They are therefore important in maintaining the integrity of the host genome. RM systems are currently classified into four types (I to IV) on the basis of differences in composition, target recognition, cofactors and the manner in which they cleave DNA. Comparing the structures of the different types, similarities can be observed suggesting an evolutionary link between these different types. This work describes the ‘deconstruction’ of a large Type I RM enzyme into forms structurally similar to smaller Type II RM enzymes in an effort to elucidate the pathway taken by Nature to form these different RM enzymes. Based upon the ability to engineer new enzymes from the Type I ‘scaffold’, an evolutionary pathway and the evolutionary pressures required to move along the pathway from Type I RM systems to Type II RM systems are proposed. Experiments to test the evolutionary model are discussed.
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Affiliation(s)
- Edward K M Bower
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - Laurie P Cooper
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - Gareth A Roberts
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - John H White
- EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3FJ, UK
| | - Yvette Luyten
- New England Biolabs, 240 County Road, Ipswich, MA 01938-2723, USA
| | - Richard D Morgan
- New England Biolabs, 240 County Road, Ipswich, MA 01938-2723, USA
| | - David T F Dryden
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
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3
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Butterer A, Pernstich C, Smith RM, Sobott F, Szczelkun MD, Tóth J. Type III restriction endonucleases are heterotrimeric: comprising one helicase-nuclease subunit and a dimeric methyltransferase that binds only one specific DNA. Nucleic Acids Res 2014; 42:5139-50. [PMID: 24510100 PMCID: PMC4005696 DOI: 10.1093/nar/gku122] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Fundamental aspects of the biochemistry of Type III restriction endonucleases remain unresolved despite being characterized by numerous research groups in the past decades. One such feature is the subunit stoichiometry of these hetero-oligomeric enzyme complexes, which has important implications for the reaction mechanism. In this study, we present a series of results obtained by native mass spectrometry and size exclusion chromatography with multi-angle light scattering consistent with a 1:2 ratio of Res to Mod subunits in the EcoP15I, EcoPI and PstII complexes as the main holoenzyme species and a 1:1 stoichiometry of specific DNA (sDNA) binding by EcoP15I and EcoPI. Our data are also consistent with a model where ATP hydrolysis activated by recognition site binding leads to release of the enzyme from the site, dissociation from the substrate via a free DNA end and cleavage of the DNA. These results are discussed critically in the light of the published literature, aiming to resolve controversies and discuss consequences in terms of the reaction mechanism.
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Affiliation(s)
- Annika Butterer
- Biomolecular & Analytical Mass Spectrometry and Center for Proteomics (CFP-CeProMa), Department of Chemistry, University of Antwerp, Antwerp 2020, Belgium and DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
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Loenen WAM, Dryden DTF, Raleigh EA, Wilson GG. Type I restriction enzymes and their relatives. Nucleic Acids Res 2014; 42:20-44. [PMID: 24068554 PMCID: PMC3874165 DOI: 10.1093/nar/gkt847] [Citation(s) in RCA: 171] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 08/26/2013] [Accepted: 08/29/2013] [Indexed: 12/24/2022] Open
Abstract
Type I restriction enzymes (REases) are large pentameric proteins with separate restriction (R), methylation (M) and DNA sequence-recognition (S) subunits. They were the first REases to be discovered and purified, but unlike the enormously useful Type II REases, they have yet to find a place in the enzymatic toolbox of molecular biologists. Type I enzymes have been difficult to characterize, but this is changing as genome analysis reveals their genes, and methylome analysis reveals their recognition sequences. Several Type I REases have been studied in detail and what has been learned about them invites greater attention. In this article, we discuss aspects of the biochemistry, biology and regulation of Type I REases, and of the mechanisms that bacteriophages and plasmids have evolved to evade them. Type I REases have a remarkable ability to change sequence specificity by domain shuffling and rearrangements. We summarize the classic experiments and observations that led to this discovery, and we discuss how this ability depends on the modular organizations of the enzymes and of their S subunits. Finally, we describe examples of Type II restriction-modification systems that have features in common with Type I enzymes, with emphasis on the varied Type IIG enzymes.
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Affiliation(s)
- Wil A. M. Loenen
- Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands, EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9, 3JJ, Scotland, UK and New England Biolabs Inc., 240 County Road Ipswich, MA 01938-2723, USA
| | - David T. F. Dryden
- Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands, EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9, 3JJ, Scotland, UK and New England Biolabs Inc., 240 County Road Ipswich, MA 01938-2723, USA
| | - Elisabeth A. Raleigh
- Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands, EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9, 3JJ, Scotland, UK and New England Biolabs Inc., 240 County Road Ipswich, MA 01938-2723, USA
| | - Geoffrey G. Wilson
- Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands, EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9, 3JJ, Scotland, UK and New England Biolabs Inc., 240 County Road Ipswich, MA 01938-2723, USA
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Vasu K, Nagaraja V. Diverse functions of restriction-modification systems in addition to cellular defense. Microbiol Mol Biol Rev 2013; 77:53-72. [PMID: 23471617 PMCID: PMC3591985 DOI: 10.1128/mmbr.00044-12] [Citation(s) in RCA: 376] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Restriction-modification (R-M) systems are ubiquitous and are often considered primitive immune systems in bacteria. Their diversity and prevalence across the prokaryotic kingdom are an indication of their success as a defense mechanism against invading genomes. However, their cellular defense function does not adequately explain the basis for their immaculate specificity in sequence recognition and nonuniform distribution, ranging from none to too many, in diverse species. The present review deals with new developments which provide insights into the roles of these enzymes in other aspects of cellular function. In this review, emphasis is placed on novel hypotheses and various findings that have not yet been dealt with in a critical review. Emerging studies indicate their role in various cellular processes other than host defense, virulence, and even controlling the rate of evolution of the organism. We also discuss how R-M systems could have successfully evolved and be involved in additional cellular portfolios, thereby increasing the relative fitness of their hosts in the population.
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Affiliation(s)
- Kommireddy Vasu
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore
| | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore
- Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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Smith RM, Jacklin AJ, Marshall JJT, Sobott F, Halford SE. Organization of the BcgI restriction-modification protein for the transfer of one methyl group to DNA. Nucleic Acids Res 2012; 41:405-17. [PMID: 23147004 PMCID: PMC3592466 DOI: 10.1093/nar/gks1000] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The Type IIB restriction–modification protein BcgI contains A and B subunits in a
2:1 ratio: A has the active sites for both endonuclease and methyltransferase functions
while B recognizes the DNA. Like almost all Type IIB systems, BcgI needs two unmethylated
sites for nuclease activity; it cuts both sites upstream and downstream of the recognition
sequence, hydrolyzing eight phosphodiester bonds in a single synaptic complex. This
complex may incorporate four A2B protomers to give the eight catalytic centres
(one per A subunit) needed to cut all eight bonds. The BcgI recognition sequence contains
one adenine in each strand that can be N6-methylated. Although most DNA
methyltransferases operate at both unmethylated and hemi-methylated sites, BcgI
methyltransferase is only effective at hemi-methylated sites, where the nuclease component
is inactive. Unlike the nuclease, the methyltransferase acts at solitary sites,
functioning catalytically rather than stoichiometrically. Though it transfers one methyl
group at a time, presumably through a single A subunit, BcgI methyltransferase can be
activated by adding extra A subunits, either individually or as part of A2B
protomers, which indicates that it requires an assembly containing at least two
A2B units.
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Affiliation(s)
- Rachel M Smith
- The DNA-protein Interactions Unit, School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
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Malygin EG, Hattman S. DNA methyltransferases: mechanistic models derived from kinetic analysis. Crit Rev Biochem Mol Biol 2012; 47:97-193. [PMID: 22260147 DOI: 10.3109/10409238.2011.620942] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The sequence-specific transfer of methyl groups from donor S-adenosyl-L-methionine (AdoMet) to certain positions of DNA-adenine or -cytosine residues by DNA methyltransferases (MTases) is a major form of epigenetic modification. It is virtually ubiquitous, except for some notable exceptions. Site-specific methylation can be regarded as a means to increase DNA information capacity and is involved in a large spectrum of biological processes. The importance of these functions necessitates a deeper understanding of the enzymatic mechanism(s) of DNA methylation. DNA MTases fall into one of two general classes; viz. amino-MTases and [C5-cytosine]-MTases. Amino-MTases, common in prokaryotes and lower eukaryotes, catalyze methylation of the exocyclic amino group of adenine ([N6-adenine]-MTase) or cytosine ([N4-cytosine]-MTase). In contrast, [C5-cytosine]-MTases methylate the cyclic carbon-5 atom of cytosine. Characteristics of DNA MTases are highly variable, differing in their affinity to their substrates or reaction products, their kinetic parameters, or other characteristics (order of substrate binding, rate limiting step in the overall reaction). It is not possible to present a unifying account of the published kinetic analyses of DNA methylation because different authors have used different substrate DNAs and/or reaction conditions. Nevertheless, it would be useful to describe those kinetic data and the mechanistic models that have been derived from them. Thus, this review considers in turn studies carried out with the most consistently and extensively investigated [N6-adenine]-, [N4-cytosine]- and [C5-cytosine]-DNA MTases.
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Affiliation(s)
- Ernst G Malygin
- Institute of Molecular Biology, State Research Center of Virology and Biotechnology Vector, Novosibirsk, Russia
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Holz-Schietinger C, Matje DM, Harrison MF, Reich NO. Oligomerization of DNMT3A controls the mechanism of de novo DNA methylation. J Biol Chem 2011; 286:41479-41488. [PMID: 21979949 PMCID: PMC3308859 DOI: 10.1074/jbc.m111.284687] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 09/26/2011] [Indexed: 01/01/2023] Open
Abstract
DNMT3A is one of two human de novo DNA methyltransferases essential for regulating gene expression through cellular development and differentiation. Here we describe the consequences of single amino acid mutations, including those implicated in the development of acute myeloid leukemia (AML) and myelodysplastic syndromes, at the DNMT3A·DNMT3A homotetramer and DNMT3A·DNMT3L heterotetramer interfaces. A model for the DNMT3A homotetramer was developed via computational interface scanning and tested using light scattering and electrophoretic mobility shift assays. Distinct oligomeric states were functionally characterized using fluorescence anisotropy and steady-state kinetics. Replacement of residues that result in DNMT3A dimers, including those identified in AML patients, show minor changes in methylation activity but lose the capacity for processive catalysis on multisite DNA substrates, unlike the highly processive wild-type enzyme. Our results are consistent with the bimodal distribution of DNA methylation in vivo and the loss of clustered methylation in AML patients. Tetramerization with the known interacting partner DNMT3L rescues processive catalysis, demonstrating that protein binding at the DNMT3A tetramer interface can modulate methylation patterning. Our results provide a structural mechanism for the regulation of DNMT3A activity and epigenetic imprinting.
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Affiliation(s)
- Celeste Holz-Schietinger
- Interdepartmental Program in Biomolecular Science & Engineering, University of California, Santa Barbara, California 93106-9510
| | - Douglas M Matje
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106-9510
| | - Madeleine Flexer Harrison
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106-9510
| | - Norbert O Reich
- Interdepartmental Program in Biomolecular Science & Engineering, University of California, Santa Barbara, California 93106-9510; Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106-9510.
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Bheemanaik S, Sistla S, Krishnamurthy V, Arathi S, Desirazu NR. Kinetics of Methylation by EcoP1I DNA Methyltransferase. Enzyme Res 2010; 2010:302731. [PMID: 21048863 PMCID: PMC2962900 DOI: 10.4061/2010/302731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2010] [Accepted: 06/21/2010] [Indexed: 11/20/2022] Open
Abstract
EcoP1I DNA MTase (M.EcoP1I), an N6-adenine MTase from bacteriophage P1, is a part of the EcoP1I restriction-modification (R-M) system which belongs to the Type III R-M system. It recognizes the sequence 5′-AGACC-3′ and methylates the internal adenine. M.EcoP1I requires Mg2+ for the transfer of methyl groups to DNA. M.EcoP1I is shown to exist as dimer in solution, and even at high salt concentrations (0.5 M) the dimeric M.EcoP1I does not dissociate into monomers suggesting a strong interaction between the monomer subunits. Preincubation and isotope partitioning studies with M.EcoP1I indicate a kinetic mechanism where the duplex DNA binds first followed by AdoMet. Interestingly, M.EcoP1I methylates DNA substrates in the presence of Mn2+ and Ca2+ other than Mg2+ with varying affinities. Amino acid analysis and methylation assays in the presence of metal ions suggest that M.EcoP1I has indeed two metal ion-binding sites [358ID(x)n … ExK401 and 600DxDxD604 motif]. EcoP1I DNA MTase catalyzes the transfer of methyl groups using a distributive mode of methylation on DNA containing more than one recognition site. A chemical modification of EcoP1I DNA MTase using N-ethylmaleimide resulted in an irreversible inactivation of enzyme activity suggesting the possible role of cysteine residues in catalysis.
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Madhusoodanan UK, Rao DN. Diversity of DNA methyltransferases that recognize asymmetric target sequences. Crit Rev Biochem Mol Biol 2010; 45:125-45. [PMID: 20184512 DOI: 10.3109/10409231003628007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
DNA methyltransferases (MTases) are a group of enzymes that catalyze the methyl group transfer from S-adenosyl-L-methionine in a sequence-specific manner. Orthodox Type II DNA MTases usually recognize palindromic DNA sequences and add a methyl group to the target base (either adenine or cytosine) on both strands. However, there are a number of MTases that recognize asymmetric target sequences and differ in their subunit organization. In a bacterial cell, after each round of replication, the substrate for any MTase is hemimethylated DNA, and it therefore needs only a single methylation event to restore the fully methylated state. This is in consistent with the fact that most of the DNA MTases studied exist as monomers in solution. Multiple lines of evidence suggest that some DNA MTases function as dimers. Further, functional analysis of many restriction-modification systems showed the presence of more than one or fused MTase genes. It was proposed that presence of two MTases responsible for the recognition and methylation of asymmetric sequences would protect the nascent strands generated during DNA replication from cognate restriction endonuclease. In this review, MTases recognizing asymmetric sequences have been grouped into different subgroups based on their unique properties. Detailed characterization of these unusual MTases would help in better understanding of their specific biological roles and mechanisms of action. The rapid progress made by the genome sequencing of bacteria and archaea may accelerate the identification and study of species- and strain-specific MTases of host-adapted bacteria and their roles in pathogenic mechanisms.
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