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Zylicz-Stachula A, Zebrowska J, Czajkowska E, Wrese W, Sulecka E, Skowron PM. Engineering TaqII bifunctional endonuclease DNA recognition fidelity: the effect of a single amino acid substitution within the methyltransferase catalytic site. Mol Biol Rep 2016; 43:269-82. [PMID: 26886214 DOI: 10.1007/s11033-016-3949-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 02/08/2016] [Indexed: 01/04/2023]
Abstract
The aim of this study was to improve a useful molecular tool-TaqII restriction endonuclease-methyltransferase-by rational protein engineering, as well as to show an application of our novel method of restriction endonuclease activity modulation through a single amino acid change in the NPPY motif of methyltransferase. An amino acid change was introduced using site-directed mutagenesis into the taqIIRM gene. The mutated gene was expressed in Escherichia coli. The protein variant was purified and characterized. Previously, we described a TspGWI variant with an amino acid change in the methyltransferase motif IV. Here, we investigate a complex, pleiotropic effect of an analogous amino acid change on its homologue-TaqII. The methyltransferase activity is reduced, but not abolished, while TaqII restriction endonuclease can be reactivated by sinefungin, with an increased DNA recognition fidelity. The general method for engineering of the IIS/IIC/IIG restriction endonuclease activity/fidelity is developed along with the generation of an improved TaqII enzyme for biotechnological applications. A successful application of our novel strategy for restriction endonuclease activity/fidelity alteration, based on bioinformatics analyses, mutagenesis and the use of cofactor-analogue activity modulation, is presented.
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Affiliation(s)
- Agnieszka Zylicz-Stachula
- Department of Molecular Biotechnology, Institute for Environmental and Human Health Protection, Division of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308, Gdańsk, Poland.
| | - Joanna Zebrowska
- Department of Molecular Biotechnology, Institute for Environmental and Human Health Protection, Division of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308, Gdańsk, Poland.
| | - Edyta Czajkowska
- Department of Molecular Biotechnology, Institute for Environmental and Human Health Protection, Division of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308, Gdańsk, Poland.
| | - Weronika Wrese
- Department of Molecular Biotechnology, Institute for Environmental and Human Health Protection, Division of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308, Gdańsk, Poland.
| | - Ewa Sulecka
- Department of Molecular Biotechnology, Institute for Environmental and Human Health Protection, Division of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308, Gdańsk, Poland.
| | - Piotr M Skowron
- Department of Molecular Biotechnology, Institute for Environmental and Human Health Protection, Division of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308, Gdańsk, Poland.
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Rezulak M, Borsuk I, Mruk I. Natural C-independent expression of restriction endonuclease in a C protein-associated restriction-modification system. Nucleic Acids Res 2015; 44:2646-60. [PMID: 26656489 PMCID: PMC4824078 DOI: 10.1093/nar/gkv1331] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 11/13/2015] [Indexed: 12/24/2022] Open
Abstract
Restriction-modification (R-M) systems are highly prevalent among bacteria and archaea, and appear to play crucial roles in modulating horizontal gene transfer and protection against phage. There is much to learn about these diverse enzymes systems, especially their regulation. Type II R-M systems specify two independent enzymes: a restriction endonuclease (REase) and protective DNA methyltransferase (MTase). Their activities need to be finely balanced in vivo Some R-M systems rely on specialized transcription factors called C (controller) proteins. These proteins play a vital role in the temporal regulation of R-M gene expression, and function to indirectly modulate the horizontal transfer of their genes across the species. We report novel regulation of a C-responsive R-M system that involves a C protein of a poorly-studied structural class - C.Csp231I. Here, the C and REase genes share a bicistronic transcript, and some of the transcriptional auto-control features seen in other C-regulated R-M systems are conserved. However, separate tandem promoters drive most transcription of the REase gene, a distinctive property not seen in other tested C-linked R-M systems. Further, C protein only partially controls REase expression, yet plays a role in system stability and propagation. Consequently, high REase activity was observed after deletion of the entire C gene, and cells bearing the ΔC R-M system were outcompeted in mixed culture assays by those with the WT R-M system. Overall, our data reveal unexpected regulatory variation among R-M systems.
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Affiliation(s)
- Monika Rezulak
- Department of Microbiology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Izabela Borsuk
- Department of Microbiology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Iwona Mruk
- Department of Microbiology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
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Oliveira PH, Touchon M, Rocha EPC. The interplay of restriction-modification systems with mobile genetic elements and their prokaryotic hosts. Nucleic Acids Res 2014; 42:10618-31. [PMID: 25120263 PMCID: PMC4176335 DOI: 10.1093/nar/gku734] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 07/29/2014] [Accepted: 07/30/2014] [Indexed: 01/21/2023] Open
Abstract
The roles of restriction-modification (R-M) systems in providing immunity against horizontal gene transfer (HGT) and in stabilizing mobile genetic elements (MGEs) have been much debated. However, few studies have precisely addressed the distribution of these systems in light of HGT, its mechanisms and its vectors. We analyzed the distribution of R-M systems in 2261 prokaryote genomes and found their frequency to be strongly dependent on the presence of MGEs, CRISPR-Cas systems, integrons and natural transformation. Yet R-M systems are rare in plasmids, in prophages and nearly absent from other phages. Their abundance depends on genome size for small genomes where it relates with HGT but saturates at two occurrences per genome. Chromosomal R-M systems might evolve under cycles of purifying and relaxed selection, where sequence conservation depends on the biochemical activity and complexity of the system and total gene loss is frequent. Surprisingly, analysis of 43 pan-genomes suggests that solitary R-M genes rarely arise from the degradation of R-M systems. Solitary genes are transferred by large MGEs, whereas complete systems are more frequently transferred autonomously or in small MGEs. Our results suggest means of testing the roles for R-M systems and their associations with MGEs.
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Affiliation(s)
- Pedro H Oliveira
- Institut Pasteur, Microbial Evolutionary Genomics, Département Génomes et Génétique, Paris, France CNRS, UMR3525, Paris, France
| | - Marie Touchon
- Institut Pasteur, Microbial Evolutionary Genomics, Département Génomes et Génétique, Paris, France CNRS, UMR3525, Paris, France
| | - Eduardo P C Rocha
- Institut Pasteur, Microbial Evolutionary Genomics, Département Génomes et Génétique, Paris, France CNRS, UMR3525, Paris, France
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