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Abstract
Bacteria in the genus Staphylococcus are important targets for phage therapy due to their prevalence as pathogens and increasing antibiotic resistance. Here we review Staphylococcus outer surface features and specific phage resistance mechanisms that define the host range, the set of strains that an individual phage can potentially infect. Phage infection goes through five distinct phases: attachment, uptake, biosynthesis, assembly, and lysis. Adsorption inhibition, encompassing outer surface teichoic acid receptor alteration, elimination, or occlusion, limits successful phage attachment and entry. Restriction-modification systems (in particular, type I and IV systems), which target phage DNA inside the cell, serve as the major barriers to biosynthesis as well as transduction and horizontal gene transfer between clonal complexes and species. Resistance to late stages of infection occurs through mechanisms such as assembly interference, in which staphylococcal pathogenicity islands siphon away superinfecting phage proteins to package their own DNA. While genes responsible for teichoic acid biosynthesis, capsule, and restriction-modification are found in most Staphylococcus strains, a variety of other host range determinants (e.g., clustered regularly interspaced short palindromic repeats, abortive infection, and superinfection immunity) are sporadic. The fitness costs of phage resistance through teichoic acid structure alteration could make staphylococcal phage therapies promising, but host range prediction is complex because of the large number of genes involved, and the roles of many of these are unknown. In addition, little is known about the genetic determinants that contribute to host range expansion in the phages themselves. Future research must identify host range determinants, characterize resistance development during infection and treatment, and examine population-wide genetic background effects on resistance selection.
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Affiliation(s)
- Abraham G Moller
- Program in Microbiology and Molecular Genetics (MMG), Graduate Division of Biological and Biomedical Sciences (GDBBS), Emory University School of Medicine, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Jodi A Lindsay
- Institute of Infection and Immunity, St. George's, University of London, London, United Kingdom
| | - Timothy D Read
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
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Couturier M, Lindås AC. The DNA Methylome of the Hyperthermoacidophilic Crenarchaeon Sulfolobus acidocaldarius. Front Microbiol 2018; 9:137. [PMID: 29472906 PMCID: PMC5809426 DOI: 10.3389/fmicb.2018.00137] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 01/22/2018] [Indexed: 12/13/2022] Open
Abstract
DNA methylation is the most common epigenetic modification observed in the genomic DNA (gDNA) of prokaryotes and eukaryotes. Methylated nucleobases, N6-methyl-adenine (m6A), N4-methyl-cytosine (m4C), and 5-methyl-cytosine (m5C), detected on gDNA represent the discrimination mark between self and non-self DNA when they are part of restriction-modification systems in prokaryotes (Bacteria and Archaea). In addition, m5C in Eukaryotes and m6A in Bacteria play an important role in the regulation of key cellular processes. Although archaeal genomes present modified bases as in the two other domains of life, the significance of DNA methylations as regulatory mechanisms remains largely uncharacterized in Archaea. Here, we began by investigating the DNA methylome of Sulfolobus acidocaldarius. The strategy behind this initial study entailed the use of combined digestion assays, dot blots, and genome resequencing, which utilizes specific restriction enzymes, antibodies specifically raised against m6A and m5C and single-molecule real-time (SMRT) sequencing, respectively, to identify DNA methylations occurring in exponentially growing cells. The previously identified restriction-modification system, specific of S. acidocaldarius, was confirmed by digestion assay and SMRT sequencing while, the presence of m6A was revealed by dot blot and identified on the characteristic Dam motif by SMRT sequencing. No m5C was detected by dot blot under the conditions tested. Furthermore, by comparing the distribution of both detected methylations along the genome and, by analyzing DNA methylation profiles in synchronized cells, we investigated in which cellular pathways, in particular the cell cycle, this m6A methylation could be a key player. The analysis of sequencing data rejected a role for m6A methylation in another defense system and also raised new questions about a potential involvement of this modification in the regulation of other biological functions in S. acidocaldarius.
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Affiliation(s)
- Mohea Couturier
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Ann-Christin Lindås
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Senok AC, Somily AM, Slickers P, Raji MA, Garaween G, Shibl A, Monecke S, Ehricht R. Investigating a rare methicillin-resistant Staphylococcus aureus strain: first description of genome sequencing and molecular characterization of CC15-MRSA. Infect Drug Resist 2017; 10:307-315. [PMID: 29042801 PMCID: PMC5633289 DOI: 10.2147/idr.s145394] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Purpose Methicillin resistant Staphylococcus aureus CC15 strains (CC15-MRSA) have only been sporadically described in literature. This study was carried out to describe the genetic make-up for this rare MRSA strain. Methods Four CC15-MRSA isolates collected in Riyadh, Saudi Arabia, between 2013 and 2014 were studied. Two isolates were from clinical infection and 2 from retail meat products. Whole genome sequencing was carried out using Illumina HiSeq2500 genome analyzer. Results All the CC15-MRSA isolates had the multilocus sequence typing profile ST1535, 13–13-1–1-81-11-13, which is a single locus variant of ST15. Of the 6 contigs related to the SCC element, one comprised a recombinase gene ccrAA, ccrC-PM1, fusC and a helicase, another one included mvaS, dru, mecA and 1 had yobV and Q4LAG7. The SCC element had 5 transposase genes, namely 3 identical paralogs of tnpIS431 and 2 identical paralogs of tnpIS256. Two identical copies of a tnpIS256-based insertion element flank the aacA-aphD gene. Two copies of this insertion element were present with 1 located in the SCC element and another inserted into the sasC gene. A short 3 kb region, which lacks any bacteriophage structural genes and site-specific DNA integrase, was inserted into the hlb gene. The hsdM and the 5’-part of the hsdS gene are replaced by a copy of the hsdM/hsdS paralogs from νSaβ giving rise to a new chimeric paralog of hsdS in νSaα. Conclusion CC15-MRSA shows a novel SCCmecV/SCCfus composite element. Its variant of hsdM/hsdS probably facilitated uptake of foreign mobile genetic elements that promoted emergence of CC15-MRSA. Close surveillance is needed to monitor spread and emergence of further CC15 MRSA strains.
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Affiliation(s)
- Abiola C Senok
- Department of Basic Science, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Ali M Somily
- Department of Pathology and Laboratory Medicine, College of Medicine, King Khalid University Hospital and King Saud University, Riyadh, Saudi Arabia
| | - Peter Slickers
- Alere Technologies GmbH, Jena, Germany.,InfectoGnostics Research Campus, Jena, Germany
| | - Muhabat A Raji
- Department of Microbiology and Immunology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Ghada Garaween
- Department of Microbiology and Immunology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Atef Shibl
- Department of Microbiology and Immunology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Stefan Monecke
- Alere Technologies GmbH, Jena, Germany.,InfectoGnostics Research Campus, Jena, Germany.,Institute for Medical Microbiology and Hygiene (IMMH), Technische Universität Dresden, Dresden, Germany
| | - Ralf Ehricht
- Alere Technologies GmbH, Jena, Germany.,InfectoGnostics Research Campus, Jena, Germany
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Hyaluronan Modulation Impacts Staphylococcus aureus Biofilm Infection. Infect Immun 2016; 84:1917-1929. [PMID: 27068096 DOI: 10.1128/iai.01418-15] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 04/06/2016] [Indexed: 01/06/2023] Open
Abstract
Staphylococcus aureus is a leading cause of chronic biofilm infections. Hyaluronic acid (HA) is a large glycosaminoglycan abundant in mammalian tissues that has been shown to enhance biofilm formation in multiple Gram-positive pathogens. We observed that HA accumulated in an S. aureus biofilm infection using a murine implant-associated infection model and that HA levels increased in a mutant strain lacking hyaluronidase (HysA). S. aureus secretes HysA in order to cleave HA during infection. Through in vitro biofilm studies with HA, the hysA mutant was found to accumulate increased biofilm biomass compared to the wild type, and confocal microscopy showed that HA is incorporated into the biofilm matrix. Exogenous addition of purified HysA enzyme dispersed HA-containing biofilms, while catalytically inactive enzyme had no impact. Additionally, induction of hysA expression prevented biofilm formation and also dispersed an established biofilm in the presence of HA. These observations were corroborated in the implant model, where there was decreased dissemination from an hysA mutant biofilm infection compared to the S. aureus wild type. Histopathology demonstrated that infection with an hysA mutant caused significantly reduced distribution of tissue inflammation compared to wild-type infection. To extend these studies, the impact of HA and S. aureus HysA on biofilm-like aggregates found in joint infections was examined. We found that HA contributes to the formation of synovial fluid aggregates, and HysA can disrupt aggregate formation. Taken together, these studies demonstrate that HA is a relevant component of the S. aureus biofilm matrix and HysA is important for dissemination from a biofilm infection.
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Dyachenko OV, Tarlachkov SV, Marinitch DV, Shevchuk TV, Buryanov YI. Expression of exogenous DNA methyltransferases: application in molecular and cell biology. BIOCHEMISTRY (MOSCOW) 2015; 79:77-87. [PMID: 24794723 DOI: 10.1134/s0006297914020011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
DNA methyltransferases might be used as powerful tools for studies in molecular and cell biology due to their ability to recognize and modify nitrogen bases in specific sequences of the genome. Methylation of the eukaryotic genome using exogenous DNA methyltransferases appears to be a promising approach for studies on chromatin structure. Currently, the development of new methods for targeted methylation of specific genetic loci using DNA methyltransferases fused with DNA-binding proteins is especially interesting. In the present review, expression of exogenous DNA methyltransferase for purposes of in vivo analysis of the functional chromatin structure along with investigation of the functional role of DNA methylation in cell processes are discussed, as well as future prospects for application of DNA methyltransferases in epigenetic therapy and in plant selection.
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Affiliation(s)
- O V Dyachenko
- Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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Abstract
Whole genome sequencing and microarrays have revealed the population structure of Staphylococcus aureus, and identified epidemiological shifts, transmission routes, and adaptation of major clones. S. aureus genomes are highly diverse. This is partly due to a population structure of conserved lineages, each with unique combinations of genes encoding surface proteins, regulators, immune evasion and virulence pathways. Even more variable are the mobile genetic elements (MGE), which encode key proteins for antibiotic resistance, virulence and host-adaptation. MGEs can transfer at high frequency between isolates of the same lineage by horizontal gene transfer (HGT). There is increasing evidence that HGT is key to bacterial adaptation and success. Recent studies have shed light on new mechanisms of DNA transfer such as transformation, the identification of receptors for transduction, on integration of DNA pathways, mechanisms blocking transfer including CRISPR and new restriction systems, strategies for evasion of restriction barriers, as well as factors influencing MGE selection and stability. These studies have also lead to new tools enabling construction of genetically modified clinical S. aureus isolates. This review will focus on HGT mechanisms and their importance in shaping the evolution of new clones adapted to antibiotic resistance, healthcare, communities and livestock.
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Abstract
Staphylococcus aureus is a ubiquitous bacterial pathogen that is the causative agent of numerous acute and chronic infections. S. aureus colonizes the anterior nares of a significant portion of the healthy adult population, but the mechanisms of colonization remain incompletely defined. Sialic acid (N-acetylneuraminic acid [Neu5Ac]) is a bioavailable carbon and nitrogen source that is abundant on mucosal surfaces and in secretions in the commensal environment. Our findings demonstrate that Neu5Ac can serve as an S. aureus carbon source, and we have identified a previously uncharacterized chromosomal locus (nan) that is required for Neu5Ac utilization. Molecular characterization of the nan locus indicates that it contains five genes, organized into four transcripts, and the genes were renamed nanE, nanR, nanK, nanA, and nanT. Initial studies with gene deletions indicate that nanT, predicted to encode the Neu5Ac transporter, and nanA and nanE, predicted to encode catabolic enzymes, are essential for growth on Neu5Ac. Furthermore, a nanE deletion mutant exhibits a growth inhibition phenotype in the presence of Neu5Ac. Transcriptional fusions and Northern blot analyses indicate that NanR represses the expression of both the nanAT and nanE transcripts, which can be relieved with Neu5Ac. Electrophoretic mobility studies demonstrate that NanR binds to the nanAT and nanE promoter regions, and the Neu5Ac catabolic intermediate N-acetylmannosamine-6-phosphate (ManNAc-6P) relieves NanR promoter binding. Taken together, these data indicate that the nan gene cluster is essential for Neu5Ac utilization and may perform an important function for S. aureus survival in the host.
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Wang R, Khan BA, Cheung GYC, Bach THL, Jameson-Lee M, Kong KF, Queck SY, Otto M. Staphylococcus epidermidis surfactant peptides promote biofilm maturation and dissemination of biofilm-associated infection in mice. J Clin Invest 2010; 121:238-48. [PMID: 21135501 DOI: 10.1172/jci42520] [Citation(s) in RCA: 208] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 10/20/2010] [Indexed: 01/12/2023] Open
Abstract
Biofilms are surface-attached agglomerations of microorganisms embedded in an extracellular matrix. Biofilm-associated infections are difficult to eradicate and represent a significant reservoir for disseminating and recurring serious infections. Infections involving biofilms frequently develop on indwelling medical devices in hospitalized patients, and Staphylococcus epidermidis is the leading cause of infection in this setting. However, the molecular determinants of biofilm dissemination are unknown. Here we have demonstrated that specific secreted, surfactant-like S. epidermidis peptides--the β subclass of phenol-soluble modulins (PSMs)--promote S. epidermidis biofilm structuring and detachment in vitro and dissemination from colonized catheters in a mouse model of device-related infection. Our study establishes in vivo significance of biofilm detachment mechanisms for the systemic spread of biofilm-associated infection and identifies the effectors of biofilm maturation and detachment in a premier biofilm-forming pathogen. Furthermore, by demonstrating that antibodies against PSMβ peptides inhibited bacterial spread from indwelling medical devices, we have provided proof of principle that interfering with biofilm detachment mechanisms may prevent dissemination of biofilm-associated infection.
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Affiliation(s)
- Rong Wang
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, USA
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Differences in methylation at GATC sites in genomic DNA of Campylobacter coli from turkeys and swine. Appl Environ Microbiol 2010; 76:7314-7. [PMID: 20833787 DOI: 10.1128/aem.00934-10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A significant fraction (46/108, 43%) of swine isolates of Campylobacter coli but none of 81 isolates of C. coli from turkeys had genomic DNA that was resistant to digestion by MboI, suggesting methylation of adenines at GATC sites. No consistent association was noted between antimicrobial resistance and MboI resistance. Seven swine-associated multilocus sequence typing-based sequence types (STs) were detected among multiple isolates with MboI-resistant DNA. The data suggest host-associated DNA modification system(s) specific for adenine at GATC sites in C. coli from swine.
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Conservation of genomic localization and sequence content of Sau3AI-like restriction-modification gene cassettes among Listeria monocytogenes epidemic clone I and selected strains of serotype 1/2a. Appl Environ Microbiol 2010; 76:5577-84. [PMID: 20581194 DOI: 10.1128/aem.00648-10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Listeria monocytogenes is a food-borne pathogen with a clonal population structure and apparently limited gene flow between strains of different lineages. Strains of epidemic clone I (ECI) have been responsible for numerous outbreaks and invariably have DNA that is resistant to digestion by Sau3AI, suggesting methylation of cytosine at GATC sites. A putative restriction-modification (RM) gene cassette has been identified in the genome of the ECI strain F2365 and all other tested ECI strains but is absent from other strains of the same serotype (4b). Homologous RM cassettes have not been reported among L. monocytogenes isolates of other serotypes. Furthermore, conclusive evidence for the involvement of this RM cassette in the Sau3AI resistance phenotype of ECI strains has been lacking. In this study, we describe a highly conserved RM cassette in certain strains of serotypes 1/2a and 4a that have Sau3AI-resistant DNA. In these strains the RM cassette was in the same genomic location as in the ECI reference strain F2365. The cassette included a gene encoding a putative recombinase, suggesting insertion via site-specific recombination. Deletion of the RM cassette in the ECI strain F2365 and the serotype 1/2a strain A7 rendered the DNA of both strains susceptible to Sau3AI digestion, providing conclusive evidence that the cassette includes a gene required for methylation of cytosine at GATC sites in both strains. The findings suggest that, in addition to its presence in ECI strains, this RM cassette and the accompanying genomic DNA methylation is also encountered among selected strains of other lineages.
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Staphylococcus aureus mutant screen reveals interaction of the human antimicrobial peptide dermcidin with membrane phospholipids. Antimicrob Agents Chemother 2009; 53:4200-10. [PMID: 19596877 DOI: 10.1128/aac.00428-09] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antimicrobial peptides (AMPs) form an important part of the innate host defense. In contrast to most AMPs, human dermcidin has an anionic net charge. To investigate whether bacteria have developed specific mechanisms of resistance to dermcidin, we screened for mutants of the leading human pathogen, Staphylococcus aureus, with altered resistance to dermcidin. To that end, we constructed a plasmid for use in mariner-based transposon mutagenesis and developed a high-throughput cell viability screening method based on luminescence. In a large screen, we did not find mutants with strongly increased susceptibility to dermcidin, indicating that S. aureus has no specific mechanism of resistance to this AMP. Furthermore, we detected a mutation in a gene of unknown function that resulted in significantly increased resistance to dermcidin. The mutant strain had an altered membrane phospholipid pattern and showed decreased binding of dermcidin to the bacterial surface, indicating that dermcidin interacts with membrane phospholipids. The mode of this interaction was direct, as shown by assays of dermcidin binding to phospholipid preparations, and specific, as the resistance to other AMPs was not affected. Our findings indicate that dermcidin has an exceptional value for the human innate host defense and lend support to the idea that it evolved to evade bacterial resistance mechanisms targeted at the cationic character of most AMPs. Moreover, they suggest that the antimicrobial activity of dermcidin is dependent on the interaction with the bacterial membrane and might thus assist with the determination of the yet unknown mode of action of this important human AMP.
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Li M, Cha DJ, Lai Y, Villaruz AE, Sturdevant DE, Otto M. The antimicrobial peptide-sensing system aps of Staphylococcus aureus. Mol Microbiol 2007; 66:1136-47. [PMID: 17961141 DOI: 10.1111/j.1365-2958.2007.05986.x] [Citation(s) in RCA: 227] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Staphylococcus aureus is a leading cause of hospital-associated and, more recently, community-associated infections caused by highly virulent methicillin-resistant strains (CA-MRSA). S. aureus survival in the human host is largely defined by the ability to evade attacks by antimicrobial peptides (AMPs) and other mechanisms of innate host defence. Here we show that AMPs induce resistance mechanisms in CA-MRSA via the aps AMP sensor/regulator system, including (i) the d-alanylation of teichoic acids, (ii) the incorporation of lysyl-phosphatidylglycerol in the bacterial membrane and a concomitant increase in lysine biosynthesis, and (iii) putative AMP transport systems such as the vraFG transporter, for which we demonstrate a function in AMP resistance. In contrast to the aps system of S. epidermidis, induction of the aps response in S. aureus was AMP-selective due to structural differences in the AMP binding loop of the ApsS sensor protein. Finally, using a murine infection model, we demonstrate the importance of the aps regulatory system in S. aureus infection. This study shows that while significant interspecies differences exist in the AMP-aps interaction, the AMP sensor system aps is functional and efficient in promoting resistance to a variety of AMPs in a clinically relevant strain of the important human pathogen S. aureus.
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Affiliation(s)
- Min Li
- Laboratory of Human Bacterial Pathogenesis, Genomics Unit, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Hamilton, Montana, USA
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Waldron DE, Lindsay JA. Sau1: a novel lineage-specific type I restriction-modification system that blocks horizontal gene transfer into Staphylococcus aureus and between S. aureus isolates of different lineages. J Bacteriol 2006; 188:5578-85. [PMID: 16855248 PMCID: PMC1540015 DOI: 10.1128/jb.00418-06] [Citation(s) in RCA: 227] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Accepted: 05/23/2006] [Indexed: 11/20/2022] Open
Abstract
The Sau1 type I restriction-modification system is found on the chromosome of all nine sequenced strains of Staphylococcus aureus and includes a single hsdR (restriction) gene and two copies of hsdM (modification) and hsdS (sequence specificity) genes. The strain S. aureus RN4220 is a vital intermediate for laboratory S. aureus manipulation, as it can accept plasmid DNA from Escherichia coli. We show that it carries a mutation in the sau1hsdR gene and that complementation restored a nontransformable phenotype. Sau1 was also responsible for reduced conjugative transfer from enterococci, a model of vancomycin resistance transfer. This may explain why only four vancomycin-resistant S. aureus strains have been identified despite substantial selective pressure in the clinical setting. Using a multistrain S. aureus microarray, we show that the two copies of sequence specificity genes (sau1hsdS1 and sau1hsdS2) vary substantially between isolates and that the variation corresponds to the 10 dominant S. aureus lineages. Thus, RN4220 complemented with sau1hsdR was resistant to bacteriophage lysis but only if the phage was grown on S. aureus of a different lineage. Similarly, it could be transduced with DNA from its own lineage but not with the phage grown on different S. aureus lineages. Therefore, we propose that Sau1 is the major mechanism for blocking transfer of resistance genes and other mobile genetic elements into S. aureus isolates from other species, as well as for controlling the spread of resistance genes between isolates of different S. aureus lineages. Blocking Sau1 should also allow genetic manipulation of clinical strains of S. aureus.
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Affiliation(s)
- Denise E Waldron
- Centre for Infection, Department of Cellular and Molecular Medicine, St. George's, University of London, Cranmer Terrace, London SW17 0RE, United Kingdom
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Buryanov Y, Shevchuk T. The use of prokaryotic DNA methyltransferases as experimental and analytical tools in modern biology. Anal Biochem 2005; 338:1-11. [PMID: 15707929 DOI: 10.1016/j.ab.2004.02.048] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2003] [Indexed: 11/23/2022]
Abstract
Prokaryotic DNA methyltransferases (MTases) are used as experimental and research tools in molecular biology and molecular genetics due to their ability to recognize and transfer methyl groups to target bases in specific DNA sequences. As a practical tool, prokaryotic DNA MTases can be used in recombinant DNA technology for in vitro alteration and enhancing of cleavage specificity of restriction endonucleases. The ability of prokaryotic DNA MTases to methylate cytosine residues in specific sequences, which are also methylated in eukaryotic DNA, makes it possible to use them as analytical reagent for determination of the site-specific level of methylation in eukaryotic DNA. In vivo DNA methylation by prokaryotic DNA MTases is used in different techniques for probing chromatin structure and protein-DNA interactions. Additional prospects are opened by development of the methods of DNA methylation targeted to predetermined DNA sequences by fusion of DNA MTases to DNA binding proteins. This review will discuss the application of prokaryotic DNA MTases of Type II in the methods and approaches mentioned above.
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Affiliation(s)
- Yaroslav Buryanov
- Shemyakin-Ovchinnikov Institute of Bioorganik Chemistry, Pushchino Branch, Russian Academy of Sciences, 142290 Pushchino, Moscow oblast, Russia
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Yildirim S, Lin W, Hitchins AD, Jaykus LA, Altermann E, Klaenhammer TR, Kathariou S. Epidemic clone I-specific genetic markers in strains of Listeria monocytogenes serotype 4b from foods. Appl Environ Microbiol 2004; 70:4158-64. [PMID: 15240296 PMCID: PMC444779 DOI: 10.1128/aem.70.7.4158-4164.2004] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2003] [Accepted: 03/08/2004] [Indexed: 11/20/2022] Open
Abstract
Listeria monocytogenes contamination of ready-to-eat foods has been implicated in numerous outbreaks of food-borne listeriosis. However, the health hazards posed by L. monocytogenes detected in foods may vary, and speculations exist that strains actually implicated in illness may constitute only a fraction of those that contaminate foods. In this study, examination of 34 serogroup 4 (putative or confirmed serotype 4b) isolates of L. monocytogenes obtained from various foods and food-processing environments, without known implication in illness, revealed that many of these strains had methylation of cytosines at GATC sites in the genome, rendering their DNA resistant to digestion by the restriction endonuclease Sau3AI. These strains also harbored a gene cassette with putative restriction-modification system genes as well as other, genomically unlinked genetic markers characteristic of the major epidemic-associated lineage of L. monocytogenes (epidemic clone I), implicated in numerous outbreaks in Europe and North America. This may reflect a relatively high fitness of strains with these genetic markers in foods and food-related environments relative to other serotype 4b strains and may partially account for the repeated involvement of such strains in human food-borne listeriosis.
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Affiliation(s)
- Suleyman Yildirim
- North Carolina State University, Department of Food Science, Campus Box 7624, Raleigh, NC 27695-7624, USA
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Mruk I, Kaczorowski T. Genetic organization and molecular analysis of the EcoVIII restriction-modification system of Escherichia coli E1585-68 and its comparison with isospecific homologs. Appl Environ Microbiol 2003; 69:2638-50. [PMID: 12732532 PMCID: PMC154532 DOI: 10.1128/aem.69.5.2638-2650.2003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2002] [Accepted: 02/20/2003] [Indexed: 11/20/2022] Open
Abstract
The EcoVIII restriction-modification (R-M) system is carried by the Escherichia coli E1585-68 natural plasmid pEC156 (4,312 bp). The two genes were cloned and characterized. The G+C content of the EcoVIII R-M system is 36.1%, which is significantly lower than the average G+C content of either plasmid pEC156 (43.6%) or E. coli genomic DNA (50.8%). The difference suggests that there is a possibility that the EcoVIII R-M system was recently acquired by the genome. The 921-bp EcoVIII endonuclease (R. EcoVIII) gene (ecoVIIIR) encodes a 307-amino-acid protein with an M(r) of 35,554. The convergently oriented EcoVIII methyltransferase (M. EcoVIII) gene (ecoVIIIM) consists of 912 bp that code for a 304-amino-acid protein with an M(r) of 33,930. The exact positions of the start codon AUG were determined by protein microsequencing. Both enzymes recognize the specific palindromic sequence 5'-AAGCTT-3'. Preparations of EcoVIII R-M enzymes purified to homogeneity were characterized. R. EcoVIII acts as a dimer and cleaves a specific sequence between two adenine residues, leaving 4-nucleotide 5' protruding ends. M. EcoVIII functions as a monomer and modifies the first adenine residue at the 5' end of the specific sequence to N(6)-methyladenine. These enzymes are thus functionally identical to the corresponding enzymes of the HindIII (Haemophilus influenzae Rd) and LlaCI (Lactococcus lactis subsp. cremoris W15) R-M systems. This finding is reflected by the levels of homology of M. EcoVIII with M. HindIII and M. LlaCI at the amino acid sequence level (50 and 62%, respectively) and by the presence of nine sequence motifs conserved among m(6) N-adenine beta-class methyltransferases. The deduced amino acid sequence of R. EcoVIII shows weak homology with its two isoschizomers, R. HindIII (26%) and R. LlaCI (17%). A catalytic sequence motif characteristic of restriction endonucleases was found in the primary structure of R. EcoVIII (D(108)X(12)DXK(123)), as well as in the primary structures of R. LlaCI and R. HindIII. Polyclonal antibodies raised against R. EcoVIII did not react with R. HindIII, while anti-M. EcoVIII antibodies cross-reacted with M. LlaCI but not with M. HindIII. R. EcoVIII requires Mg(II) ions for phosphodiester bond cleavage. We found that the same ions are strong inhibitors of the M. EcoVIII enzyme. The biological implications of this finding are discussed.
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Affiliation(s)
- Iwona Mruk
- Department of Microbiology, University of Gdańsk, Kladki 24, 80-822 Gdańsk, Poland
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17
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Friedhoff P, Thomas E, Pingoud A. Tyr212: a key residue involved in strand discrimination by the DNA mismatch repair endonuclease MutH. J Mol Biol 2003; 325:285-97. [PMID: 12488096 DOI: 10.1016/s0022-2836(02)01224-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The molecular mechanism of how the dam-methylation status of the DNA is recognized during DNA mismatch repair by the strand discrimination endonuclease MutH is not known. A comparison of the crystal structure of MutH with those of co-crystal structures of several restriction endonucleases, together with a multiple sequence alignment of MutH and related proteins suggested that Phe94, Arg184 and Tyr212 could be involved in discrimination between a methylated or unmethylated adenine in the d(GATC) sequence. A mutational analysis revealed that the variants R184A and Y212S, but not F94A, were substantially reduced in their ability to complement a mismatch repair deficiency in a mutH(-) Escherichia coli strain. In vitro, R184A displayed a strongly reduced endonuclease activity, whereas the Y212S variant has almost completely lost its preference for cleaving the unmethylated strand at hemimethylated d(GATC) sites. Furthermore, the Y212 variant can cleave fully methlyated d(GATC) sites at a comparable rate to unmethylated d(GATC) sites. This demonstrates that Tyr212 is an important, if not the only amino acid residue in MutH for sensing the methylation status of the DNA.
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Affiliation(s)
- Peter Friedhoff
- Institut für Biochemie (FB 08), Justus-Liebig-Universität, D-35392 Giessen, Germany.
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18
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Pingoud A, Jeltsch A. Structure and function of type II restriction endonucleases. Nucleic Acids Res 2001; 29:3705-27. [PMID: 11557805 PMCID: PMC55916 DOI: 10.1093/nar/29.18.3705] [Citation(s) in RCA: 432] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2001] [Revised: 03/23/2001] [Accepted: 06/07/2001] [Indexed: 11/13/2022] Open
Abstract
More than 3000 type II restriction endonucleases have been discovered. They recognize short, usually palindromic, sequences of 4-8 bp and, in the presence of Mg(2+), cleave the DNA within or in close proximity to the recognition sequence. The orthodox type II enzymes are homodimers which recognize palindromic sites. Depending on particular features subtypes are classified. All structures of restriction enzymes show a common structural core comprising four beta-strands and one alpha-helix. Furthermore, two families of enzymes can be distinguished which are structurally very similar (EcoRI-like enzymes and EcoRV-like enzymes). Like other DNA binding proteins, restriction enzymes are capable of non-specific DNA binding, which is the prerequisite for efficient target site location by facilitated diffusion. Non-specific binding usually does not involve interactions with the bases but only with the DNA backbone. In contrast, specific binding is characterized by an intimate interplay between direct (interaction with the bases) and indirect (interaction with the backbone) readout. Typically approximately 15-20 hydrogen bonds are formed between a dimeric restriction enzyme and the bases of the recognition sequence, in addition to numerous van der Waals contacts to the bases and hydrogen bonds to the backbone, which may also be water mediated. The recognition process triggers large conformational changes of the enzyme and the DNA, which lead to the activation of the catalytic centers. In many restriction enzymes the catalytic centers, one in each subunit, are represented by the PD. D/EXK motif, in which the two carboxylates are responsible for Mg(2+) binding, the essential cofactor for the great majority of enzymes. The precise mechanism of cleavage has not yet been established for any enzyme, the main uncertainty concerns the number of Mg(2+) ions directly involved in cleavage. Cleavage in the two strands usually occurs in a concerted fashion and leads to inversion of configuration at the phosphorus. The products of the reaction are DNA fragments with a 3'-OH and a 5'-phosphate.
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Affiliation(s)
- A Pingoud
- Institut für Biochemie (FB 08), Justus-Liebig-Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany.
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19
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Cantalupo G, Bucci C, Salvatore P, Pagliarulo C, Roberti V, Lavitola A, Bruni CB, Alifano P. Evolution and function of the neisserial dam-replacing gene. FEBS Lett 2001; 495:178-83. [PMID: 11334887 DOI: 10.1016/s0014-5793(01)02388-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Phase variation through slippage-like mechanisms involving homopolymeric tracts depends in part on the absence of Dam-methylase in several pathogenic isolates of Neisseria meningitidis. In Dam-defective strains drg (dam-replacing gene), flanked by pseudo-transposable small repeated elements (SREs), replaced dam. We demonstrate that drg encodes a restriction endonuclease (NmeBII) that cleaves 5'-GmeATC-3'. drg is also present in 50% of Neisseria lactamica strains, but in most of them it is inactive because of the absence of an SRE-providing promoter. This is associated with the presence of GATmeC, suggesting an alternative restriction-modification system (RM) specific for 5'-GATC-3', similar to Sau3AI-RM of Staphylococcus aureus 3A, Lactococcus lactis KR2 and Listeria monocytogenes.
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Affiliation(s)
- G Cantalupo
- Dipartimento di Biologia e Patologia Cellulare e Moleculare L Califano, Università di Napoli Federico II, Naples, Italy
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20
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Burrus V, Bontemps C, Decaris B, Guédon G. Characterization of a novel type II restriction-modification system, Sth368I, encoded by the integrative element ICESt1 of Streptococcus thermophilus CNRZ368. Appl Environ Microbiol 2001; 67:1522-8. [PMID: 11282600 PMCID: PMC92764 DOI: 10.1128/aem.67.4.1522-1528.2001] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A novel type II restriction and modification (R-M) system, Sth368I, which confers resistance to phiST84, was found in Streptococcus thermophilus CNRZ368 but not in the very closely related strain A054. Partial sequencing of the integrative conjugative element ICESt1, carried by S. thermophilus CNRZ368 but not by A054, revealed a divergent cluster of two genes, sth368IR and sth368IM. The protein sequence encoded by sth368IR is related to the type II endonucleases R.LlaKR2I and R.Sau3AI, which recognize and cleave the sequence 5'-GATC-3'. The protein sequence encoded by sth368IM is very similar to numerous type II 5-methylcytosine methyltransferases, including M.LlaKR2I and M.Sau3AI. Cell extracts of CNRZ368 but not A054 were found to cleave at the GATC site. Furthermore, the C residue of the sequence 5'-GATC-3' was found to be methylated in CNRZ368 but not in A054. Cloning and integration of a copy of sth368IR and sth368IM in the A054 chromosome confers on this strain phenotypes similar to those of CNRZ368, i.e., phage resistance, endonuclease activity of cell extracts, and methylation of the sequence 5'-GATC-3'. Disruption of sth368IR removes resistance and restriction activity. We conclude that ICESt1 encodes an R-M system, Sth368I, which recognizes the sequence 5'-GATC-3' and is related to the Sau3AI and LlaKR2I restriction systems.
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Affiliation(s)
- V Burrus
- Laboratoire de Génétique et Microbiologie (INRA UA952), Faculté des Sciences, Université Henri Poincaré (Nancy 1), 54506 Vandoeuvre-lès-Nancy, France
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21
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Twomey DP, McKay LL, O'Sullivan DJ. Molecular characterization of the Lactococcus lactis LlaKR2I restriction-modification system and effect of an IS982 element positioned between the restriction and modification genes. J Bacteriol 1998; 180:5844-54. [PMID: 9811640 PMCID: PMC107656 DOI: 10.1128/jb.180.22.5844-5854.1998] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The nucleotide sequence of the plasmid-encoded LlaKR2I restriction-modification (R-M) system of Lactococcus lactis subsp. lactis biovar diacetylactis KR2 was determined. This R-M system comprises divergently transcribed endonuclease (llaKR2IR) and methyltransferase (llaKR2IM) genes; located in the intergenic region is a copy of the insertion element IS982, whose putative transposase gene is codirectionally transcribed with llaKR2IM. The deduced sequence of the LlaKR2I endonuclease shared homology with the type II endonuclease Sau3AI and with the MutH mismatch repair protein, both of which recognize and cleave the sequence 5' GATC 3'. In addition, M. LlaKR2I displayed homology with the 5-methylcytosine methyltransferase family of proteins, exhibiting greatest identity with M. Sau3AI. Both of these proteins shared notable homology throughout their putative target recognition domains. Furthermore, subclones of the native parental lactococcal plasmid pKR223, which encode M. LlaKR2I, all remained undigested after treatment with Sau3AI despite the presence of multiple 5' GATC 3' sites. The combination of these data suggested that the specificity of the LlaKR2I R-M system was likely to be 5' GATC 3', with the cytosine residue being modified to 5-methylcytosine. The IS982 element located within the LlaKR2I R-M system contained at its extremities two 16-bp perfect inverted repeats flanked by two 7-bp direct repeats. A perfect extended promoter consensus, which represented the likely original promoter of the llaKR2IR gene, was shown to overlap the direct repeat sequence on the other side of IS982. Specific deletion of IS982 and one of these direct repeats via a PCR strategy indicated that the LlaKR2I R-M determinants do not rely on elements within IS982 for expression and that the efficiency of bacteriophage restriction was not impaired.
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Affiliation(s)
- D P Twomey
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, Minnesota 55108, USA
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22
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Ban C, Yang W. Structural basis for MutH activation in E.coli mismatch repair and relationship of MutH to restriction endonucleases. EMBO J 1998; 17:1526-34. [PMID: 9482749 PMCID: PMC1170500 DOI: 10.1093/emboj/17.5.1526] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
MutS, MutL and MutH are the three essential proteins for initiation of methyl-directed DNA mismatch repair to correct mistakes made during DNA replication in Escherichia coli. MutH cleaves a newly synthesized and unmethylated daughter strand 5' to the sequence d(GATC) in a hemi-methylated duplex. Activation of MutH requires the recognition of a DNA mismatch by MutS and MutL. We have crystallized MutH in two space groups and solved the structures at 1.7 and 2.3 A resolution, respectively. The active site of MutH is located at an interface between two subdomains that pivot relative to one another, as revealed by comparison of the crystal structures, and this presumably regulates the nuclease activity. The relative motion of the two subdomains in MutH correlates with the position of a protruding C-terminal helix. This helix appears to act as a molecular lever through which MutS and MutL may communicate the detection of a DNA mismatch and activate MutH. With sequence homology to Sau3AI and structural similarity to PvuII endonuclease, MutH is clearly related to these enzymes by divergent evolution, and this suggests that type II restriction endonucleases evolved from a common ancestor.
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Affiliation(s)
- C Ban
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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23
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Cao W, Lu J, Barany F. Nucleotide sequences and gene organization of TaqI endonuclease isoschizomers from Thermus sp. SM32 and Thermus filiformis Tok6A1. Gene 1997; 197:205-14. [PMID: 9332368 DOI: 10.1016/s0378-1119(97)00264-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Eight TaqI isoschizomer genes, two from Yellowstone National Park, one from Japan, two from New Zealand, two from Portugal, and one from the Azores (1000 miles west of Portugal), were PCR-amplified and sequenced. Sequence alignment of isoschizomers isolated from close geographical locations shows identical or almost identical protein sequences, while isoschizomers from distant sites demonstrate considerable diversity, ranging from 54 to 75% in amino acid identity. Accordingly, these isoschizomers were arranged into four geographical groups, i.e., USA as represented by Thermus aquaticus YT1, Japan by Thermus thermophilus HB8, New Zealand by Thermus filiformis Tok6A1, Portugal by Thermus sp. SM32. The complete ORFs of two new representative genes, tfiTok6A1I and tsp32IR, were obtained by bubble PCR. Unlike M . TaqI-R.TaqI and M . TthHB8I-R . TthHB8I which exhibit an unusual 13-codon overlap, the methylase and endonuclease genes are each separated by 15 nucleotides in the TfiTok6A1I and Tsp32IR restriction-modification systems. Phylogenetic analysis suggests that initially TfiTok6A1I diverged from a common ancestor, then Tsp32IR branched out, and finally TaqI and TthHB8I diverged from each other during evolution.
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Affiliation(s)
- W Cao
- Department of Microbiology, Hearst Microbiology Research Center, Cornell University Medical College, New York, NY, USA
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24
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Ruan H, Lunnen KD, Scott ME, Moran LS, Slatko BE, Pelletier JJ, Hess EJ, Benner J, Wilson GG, Xu SY. Cloning and sequence comparison ofAvaI andBsoBI restriction-modification systems. ACTA ACUST UNITED AC 1996. [DOI: 10.1007/bf02173975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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25
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Striebel HM, Seeber S, Jarsch M, Kessler C. Cloning and characterization of the MamI restriction-modification system from Microbacterium ammoniaphilum in Escherichia coli. Gene 1996; 172:41-6. [PMID: 8654988 DOI: 10.1016/0378-1119(96)00189-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The genes encoding a class-IIN restriction-modification (R-M) system (MamI, sequence specificity [symbol: see text] from Microbacterium ammoniaphilum have been cloned in Escherichia coli. The vector used for cloning was plasmid pUC18 modified by the inclusion of three MamI recognition sites. Recombinant clones containing the mamIM gene in its genomic context became fully methylated in vivo and remained completely resistant against digestion with the R.MamI restriction endonuclease (ENase). Determination of the nucleotide (nt) sequence revealed three open reading frames with lengths of 1089 bp (ORF1), 276 bp (ORFc) and 927 bp (ORF2). On the basis of expression and deletion experiments, the 1089-bp ORF1 was assigned to mamIM encoding the M.MamI DNA methyltransferase (MTase). By amino acid sequencing of the N terminus of R.MamI and comparison of the deduced nt sequence with ORF2, the 927-bp ORF2 was identified as the mamIR gene encoding R.MamI. The 276-bp ORFc, located between mamIR and mamIM, is part of the DNA sequence downstream from mamIM shown to be necessary for controlled mamIM expression.
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Affiliation(s)
- H M Striebel
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA.
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26
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Affiliation(s)
- M P Kladde
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802, USA
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27
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Nwankwo DO. Cloning of a pair of genes encoding isoschizomeric restriction endonucleases from Bacillus species: the BspEI and BspMII restriction and modification systems. Gene 1995; 157:31-5. [PMID: 7607514 DOI: 10.1016/0378-1119(94)00573-b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The respective genes (R-M) encoding restriction and modification systems from two Bacillus species which recognise the same nucleotide sequence, 5'-TCCGGA, have been cloned and expressed in Escherichia coli. The BspEI R-M genes were cloned on a 3.6-kb HindIII fragment, whereas the BspMII R-M genes were cloned on three contiguous HindIII fragments totalling 9.8 kb. Upon thermal induction, E. coli carrying the bspEIR clones under the control of the phage lambda PL promoter, express high levels of R.BspEI (10(6) units/g wet cell paste). The bspMIIR gene, on the other hand, is only poorly expressed (about 4 x 10(3) units/g wet cell paste) following induction. Although the enzymes of both R-M systems recognize the same sequence and the restriction endonucleases (ENases) cleave DNA at the same position, the modification specified by the methyltransferases (MTases) differ. The internal cytosine is the site of M.BspMII modification (TCmeCGGA), whereas the external cytosine is modified by M.BspEI (TmeCCGGA). The two R-M systems probably evolved independently.
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Affiliation(s)
- D O Nwankwo
- New England Biolabs Inc., Beverly, MA 01915, USA
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28
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McClelland M, Nelson M, Raschke E. Effect of site-specific modification on restriction endonucleases and DNA modification methyltransferases. Nucleic Acids Res 1994; 22:3640-59. [PMID: 7937074 PMCID: PMC308336 DOI: 10.1093/nar/22.17.3640] [Citation(s) in RCA: 300] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Restriction endonucleases have site-specific interactions with DNA that can often be inhibited by site-specific DNA methylation and other site-specific DNA modifications. However, such inhibition cannot generally be predicted. The empirically acquired data on these effects are tabulated for over 320 restriction endonucleases. In addition, a table of known site-specific DNA modification methyltransferases and their specificities is presented along with EMBL database accession numbers for cloned genes.
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Affiliation(s)
- M McClelland
- California Institute of Biological Research, La Jolla 92037
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29
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Kumar S, Cheng X, Klimasauskas S, Mi S, Posfai J, Roberts RJ, Wilson GG. The DNA (cytosine-5) methyltransferases. Nucleic Acids Res 1994; 22:1-10. [PMID: 8127644 PMCID: PMC307737 DOI: 10.1093/nar/22.1.1] [Citation(s) in RCA: 336] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The m5C-MTases form a closely-knit family of enzymes in which common amino acid sequence motifs almost certainly translate into common structural and functional elements. These common elements are located predominantly in a single structural domain that performs the chemistry of the reaction. Sequence-specific DNA recognition is accomplished by a separate domain that contains recognition elements not seen in other structures. This, combined with the novel and unexpected mechanistic feature of trapping a base out of the DNA helix, makes the m5C-MTases an intriguing class of enzymes for further study. The reaction pathway has suddenly become more complicated because of the base-flipping and much remains to be learned about the DNA recognition elements in the family members for which structural information is not yet available.
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Affiliation(s)
- S Kumar
- New England Biolabs, Beverly, MA 01915
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30
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Nelson M, Raschke E, McClelland M. Effect of site-specific methylation on restriction endonucleases and DNA modification methyltransferases. Nucleic Acids Res 1993; 21:3139-54. [PMID: 8392715 PMCID: PMC309743 DOI: 10.1093/nar/21.13.3139] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- M Nelson
- California Institute of Biological Research, La Jolla 92037
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31
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Ueno T, Ito H, Kimizuka F, Kotani H, Nakajima K. Gene structure and expression of the MboI restriction--modification system. Nucleic Acids Res 1993; 21:2309-13. [PMID: 8506128 PMCID: PMC309525 DOI: 10.1093/nar/21.10.2309] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The genes from Moraxella bovis encoding the MboI restriction--modification system were cloned and expressed in Escherichia coli. Three open reading frames were found in the sequence containing the genes. These genes, which we named mboA, mboB, and mboC, had the same orientation in the genome. Genes mboA and mboC encoded MboI methyltransferases (named M.MboA and M.MboC) with 294 and 273 amino acid residues, respectively. The mboB gene coded for MboI restriction endonuclease (R.MboI) with 280 amino acid residues. Recombinant E.coli-MBOI, which contained the whole MboI system, overproduced R.MboI. R.MboI activity from E.coli-MBOI was 480-fold that of M.bovis. The amino acid sequences deduced from these genes were compared with those of other restriction--modification systems. The protein sequences of the MboI system had 38-49% homology with those of the DpnII system.
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Affiliation(s)
- T Ueno
- Bioproducts Development Center, Takara Shuzo Co., Ltd., Shiga, Japan
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32
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Janulaitis A, Vaisvila R, Timinskas A, Klimasauskas S, Butkus V. Cloning and sequence analysis of the genes coding for Eco57I type IV restriction-modification enzymes. Nucleic Acids Res 1992; 20:6051-6. [PMID: 1334261 PMCID: PMC334472 DOI: 10.1093/nar/20.22.6051] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A 6.3 kb fragment of E.coli RFL57 DNA coding for the type IV restriction-modification system Eco57I was cloned and expressed in E.coli RR1. A 5775 bp region of the cloned fragment was sequenced which contains three open reading frames (ORF). The methylase gene is 1623 bp long, corresponding to a protein of 543 amino acids (62 kDa); the endonuclease gene is 2991 bp in length (997 amino acids, 117 kDa). The two genes are transcribed convergently from different strands with their 3'-ends separated by 69 bp. The third short open reading frame (186 bp, 62 amino acids) has been identified, that precedes and overlaps by 7 nucleotides the ORF encoding the methylase. Comparison of the deduced Eco57I endonuclease and methylase amino acid sequences revealed three regions of significant similarity. Two of them resemble the conserved sequence motifs characteristic of the DNA[adenine-N6] methylases. The third one shares similarity with corresponding regions of the PaeR7I, TaqI, CviBIII, PstI, BamHI and HincII methylases. Homologs of this sequence are also found within the sequences of the PaeR7I, PstI and BamHI restriction endonucleases. This is the first example of a family of cognate restriction endonucleases and methylases sharing homologous regions. Analysis of the structural relationship suggests that the type IV enzymes represent an intermediate in the evolutionary pathway between the type III and type II enzymes.
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Affiliation(s)
- A Janulaitis
- Institute of Biotechnology FERMENTAS, Vilnius, Lithuania
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33
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McClelland M, Nelson M. Effect of site-specific methylation on DNA modification methyltransferases and restriction endonucleases. Nucleic Acids Res 1992; 20 Suppl:2145-57. [PMID: 1317957 PMCID: PMC333989 DOI: 10.1093/nar/20.suppl.2145] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- M McClelland
- California Institute of Biological Research, La Jolla, CA 92037
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34
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Barany F, Danzitz M, Zebala J, Mayer A. Cloning and sequencing of genes encoding the TthHB8I restriction and modification enzymes: comparison with the isoschizomeric TaqI enzymes. Gene 1992; 112:3-12. [PMID: 1339363 DOI: 10.1016/0378-1119(92)90296-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Genes encoding the TthHB8I restriction and modification (R-M) system from Thermus thermophilus HB8 (recognition sequence T decreases CGA) were cloned in Escherichia coli. The genes have the same transcriptional orientation, with the last 13 codons of the methyltransferase (MTase) overlapping the first 13 codons of the endonuclease (ENase). Nucleotide sequence analysis of the TthHB8I ENase revealed a single chain of 263 amino acid (aa) residues that share a 77% identity with the corrected isoschizomeric TaqI ENase. Likewise, the Tth MTase (428 aa) shares a 79% identity with the corrected sequence of the TaqI MTase. This high degree of aa conservation suggests a common origin between the Taq and Tth R-M systems. However, codon usage and G+C content for the R-M genes differed markedly from that of other cloned Thermus genes. This suggests that these R-M genes were only recently introduced into the genus Thermus.
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Affiliation(s)
- F Barany
- Department of Microbiology, Hearst Microbiology Research Center, Cornell University Medical College, New York, NY 10021
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Affiliation(s)
- G G Wilson
- New England Biolabs Inc., Beverly, Massachusetts 01915
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36
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Erdmann D, Düsterhöft A, Kröger M. Cloning and molecular characterization of the HgiCI restriction/modification system from Herpetosiphon giganteus Hpg9 reveals high similarity to BanI. EUROPEAN JOURNAL OF BIOCHEMISTRY 1991; 202:1247-56. [PMID: 1662609 DOI: 10.1111/j.1432-1033.1991.tb16497.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The genes coding for the GGYRCC specific restriction/modification system HgiCI from Herpetosiphon giganteus Hpg9 have been cloned in Escherichia coli in three steps. As an initial step, the methyltransferase gene could be obtained after heterologous in vitro selection of a plasmid gene bank by cleavage with the isoschizomeric restriction endonuclease BanI. The adjacent endonuclease gene was cloned following Southern blot analysis of flanking genomic regions. The two genes code for polypeptides of 420 amino acids (M.HgiCI) and 345 amino acids (R.HgiCI). Establishing a functional endonuclease gene could only be achieved using a tightly regulated expression system or by methylation of the genomic DNA prior to transformation of the endonuclease gene. The methyltransferase M.HgiCI shows significant similarities to the family of 5-methylcytidine methyltransferases. Striking similarities could be found with both the isoschizomeric endonuclease and methyltransferase of the BanI restriction/modification system from Bacillus aneurinolyticus.
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Affiliation(s)
- D Erdmann
- Institut für Mikrobiologie und Molekularbiologie der Justus-Liebig-Universität Giessen, Federal Republic of Germany
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Nelson M, McClelland M. Site-specific methylation: effect on DNA modification methyltransferases and restriction endonucleases. Nucleic Acids Res 1991; 19 Suppl:2045-71. [PMID: 1645875 PMCID: PMC331346 DOI: 10.1093/nar/19.suppl.2045] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- M Nelson
- California Institute of Biological Research, La Jolla 92037
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