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The functional coupling between restriction and DNA phosphorothioate modification systems underlying the DndFGH restriction complex

Abstract

Bacteria have evolved diverse mechanisms to cope with the constant threat of phage predation. DndABCDE-catalysed DNA phosphorothioate modification, in which the non-bridging oxygen of the DNA sugar-phosphate backbone is replaced by sulfur, can couple with proteins encoded by the dndFGH gene cluster to provide defensive protection, albeit via an obscure mode of action. Here we present structural and biochemical insights showing that the proteins DndF, DndG and DndH form a DndFGH complex and exhibit functions that are not detected in the individual proteins, including DNA nicking and translocation activities. Interestingly, DndFGH shows preferential affinity for phosphorothioate DNA, which suppresses the DNA-stimulated ATPase activity of the complex and consequently impedes its translocation and nicking activities. This phosphorothioate binding preference is believed to account for self/non-self discrimination and enable DndFGH to specifically introduce nicking damage in invasive DNA. This study expands our knowledge of the defence mechanisms involving epigenetic markers for the protection of self-DNA.

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Fig. 1: DndFGH provides protection against invasive parasites.
Fig. 2: DNA nicking assays of the DndFGH complex in vitro.
Fig. 3: ATPase activity of DndF and its involvement in DndFGH nicking.
Fig. 4: Structural and biochemical analyses of DndG from E. coli B7A.
Fig. 5: Structural and biochemical analyses of DndH.
Fig. 6: Effect of the translocation activity of DndH on DndFGH defence.
Fig. 7: Effects of DNA and ATP on the conformational changes of E.DndFGH.
Fig. 8: Regulation of E.DndFGH activities by DNA PT modification.

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Data availability

The data supporting the findings of this study are available from the corresponding authors upon reasonable request. The coordinates and structure factors of DndG and DndHCTD from E. coli B7A have been deposited in the Protein Data Bank under the accession numbers 7EXX and 7ES4, respectively. Source data are provided with this paper.

References

  1. Tock, M. R. & Dryden, D. T. F. The biology of restriction and anti-restriction. Curr. Opin. Microbiol. 8, 466–472 (2005).

    Article  CAS  Google Scholar 

  2. Yamaguchi, Y., Park, J. H. & Inouye, M. Toxin-antitoxin systems in bacteria and archaea. Annu. Rev. Genet. 45, 61–79 (2011).

    Article  CAS  Google Scholar 

  3. Dy, R. L., Przybilski, R., Semeijn, K., Salmond, G. P. & Fineran, P. C. A widespread bacteriophage abortive infection system functions through a type IV toxin-antitoxin mechanism. Nucleic Acids Res. 42, 4590–4605 (2014).

    Article  CAS  Google Scholar 

  4. Marraffini, L. A. CRISPR-Cas immunity in prokaryotes. Nature 526, 55–61 (2015).

    Article  CAS  Google Scholar 

  5. Swarts, D. C. et al. DNA-guided DNA interference by a prokaryotic Argonaute. Nature 507, 258–261 (2014).

    Article  CAS  Google Scholar 

  6. Thiaville, J. J. et al. Novel genomic island modifies DNA with 7-deazaguanine derivatives. Proc. Natl Acad. Sci. USA 113, E1452–E1459 (2016).

    Article  CAS  Google Scholar 

  7. Chen, K., Zhao, B. S. & He, C. Nucleic acid modifications in regulation of gene expression. Cell Chem. Biol. 23, 74–85 (2016).

    Article  CAS  Google Scholar 

  8. Wang, L. et al. Phosphorothioation of DNA in bacteria by dnd genes. Nat. Chem. Biol. 3, 709–710 (2007).

    Article  CAS  Google Scholar 

  9. Wang, L. et al. DNA phosphorothioation is widespread and quantized in bacterial genomes. Proc. Natl Acad. Sci. USA 108, 2963–2968 (2011).

    Article  CAS  Google Scholar 

  10. Zhou, X. et al. A novel DNA modification by sulphur. Mol. Microbiol. 57, 1428–1438 (2005).

    Article  CAS  Google Scholar 

  11. Eckstein, F. Phosphorothioates, essential components of therapeutic oligonucleotides. Nucleic Acid Ther. 24, 374–387 (2014).

    Article  CAS  Google Scholar 

  12. Xu, T., Yao, F., Zhou, X., Deng, Z. & You, D. A novel host-specific restriction system associated with DNA backbone S-modification in Salmonella. Nucleic Acids Res. 38, 7133–7141 (2010).

    Article  CAS  Google Scholar 

  13. Cao, B. et al. Pathological phenotypes and in vivo DNA cleavage by unrestrained activity of a phosphorothioate-based restriction system in Salmonella. Mol. Microbiol. 93, 776–785 (2014).

    Article  CAS  Google Scholar 

  14. Wang, L., Jiang, S., Deng, Z., Dedon, P. C. & Chen, S. DNA phosphorothioate modification—a new multi-functional epigenetic system in bacteria. FEMS Microbiol. Rev. 43, 109–122 (2019).

    Article  CAS  Google Scholar 

  15. Cao, B. et al. Genomic mapping of phosphorothioates reveals partial modification of short consensus sequences. Nat. Commun. 5, 3951 (2014).

    Article  CAS  Google Scholar 

  16. Chen, C. et al. Convergence of DNA methylation and phosphorothioation epigenetics in bacterial genomes. Proc. Natl Acad. Sci. USA 114, 4501–4506 (2017).

    Article  CAS  Google Scholar 

  17. Tong, T. et al. Occurrence, evolution, and functions of DNA phosphorothioate epigenetics in bacteria. Proc. Natl Acad. Sci. USA 115, E2988–E2996 (2018).

    Article  CAS  Google Scholar 

  18. Wu, X. et al. Epigenetic competition reveals density-dependent regulation and target site plasticity of phosphorothioate epigenetics in bacteria. Proc. Natl Acad. Sci. USA 117, 14322–14330 (2020).

    Article  CAS  Google Scholar 

  19. Cao, B. et al. Nick-seq for single-nucleotide resolution genomic maps of DNA modifications and damage. Nucleic Acids Res. 48, 6715–6725 (2020).

    Article  CAS  Google Scholar 

  20. Wei, Y. et al. Single-molecule optical mapping of the distribution of DNA phosphorothioate epigenetics. Nucleic Acids Res. 49, 3672–3680 (2021).

    Article  CAS  Google Scholar 

  21. Wang, S. et al. SspABCD-SspFGH constitutes a new type of DNA phosphorothioate-based bacterial defense system. mBio 12, e00613–e00621 (2021).

    Article  CAS  Google Scholar 

  22. Xiong, L. et al. A new type of DNA phosphorothioation-based antiviral system in archaea. Nat. Commun. 10, 1688 (2019).

    Article  Google Scholar 

  23. Xiong, X. et al. SspABCD–SspE is a phosphorothioation-sensing bacterial defence system with broad anti-phage activities. Nat. Microbiol. 5, 917–928 (2020).

    Article  CAS  Google Scholar 

  24. Liu, L. et al. Structural analysis of an l-cysteine desulfurase from an Ssp DNA phosphorothioation system. mBio 11, e00488 (2020).

    Article  CAS  Google Scholar 

  25. Gan, R. et al. DNA phosphorothioate modifications influence the global transcriptional response and protect DNA from double-stranded breaks. Sci. Rep. 4, 6642 (2014).

    Article  CAS  Google Scholar 

  26. Sharma, D. et al. Role of the conserved lysine within the Walker A motif of human DMC1. DNA Repair (Amst). 12, 53–62 (2013).

    Article  CAS  Google Scholar 

  27. Kutnowski, N. et al. The 3-D structure of VNG0258H/RosR—A haloarchaeal DNA-binding protein in its ionic shell. J. Struct. Biol. 204, 191–198 (2018).

    Article  CAS  Google Scholar 

  28. Steczkiewicz, K., Muszewska, A., Knizewski, L., Rychlewski, L. & Ginalski, K. Sequence, structure and functional diversity of PD-(D/E)XK phosphodiesterase superfamily. Nucleic Acids Res. 40, 7016–7045 (2012).

    Article  CAS  Google Scholar 

  29. Pena, A. et al. The hexameric structure of a conjugative VirB4 protein ATPase provides new insights for a functional and phylogenetic relationship with DNA translocases. J. Biol. Chem. 287, 39925–39932 (2012).

    Article  CAS  Google Scholar 

  30. Byrne, R. T., Schuller, J. M., Unverdorben, P., Forster, F. & Hopfner, K. P. Molecular architecture of the HerA–NurA DNA double-strand break resection complex. FEBS Lett. 588, 4637–4644 (2014).

    Article  CAS  Google Scholar 

  31. Matilla, I. et al. The conjugative DNA translocase TrwB is a structure-specific DNA-binding protein. J. Biol. Chem. 285, 17537–17544 (2010).

    Article  CAS  Google Scholar 

  32. Morris, P. D. & Raney, K. D. DNA helicases displace streptavidin from biotin-labeled oligonucleotides. Biochemistry 38, 5164–5171 (1999).

    Article  CAS  Google Scholar 

  33. Zou, X. et al. Systematic strategies for developing phage resistant Escherichia coli strains. Nat. Commun. 13, 4491 (2022).

    Article  CAS  Google Scholar 

  34. Liu, G. et al. Structural basis for the recognition of sulfur in phosphorothioated DNA. Nat. Commun. 9, 4689 (2018).

    Article  Google Scholar 

  35. Chand, M. K. et al. Translocation-coupled DNA cleavage by the Type ISP restriction-modification enzymes. Nat. Chem. Biol. 11, 870–877 (2015).

    Article  CAS  Google Scholar 

  36. Otwinowski, Z. & Minor, W. Processing of X-ray diffraction data collected in oscillation mode. Methods Enzymol. 276, 307–326 (1997).

    Article  CAS  Google Scholar 

  37. Adams, P. D. et al. PHENIX: building new software for automated crystallographic structure determination. Acta Crystallogr. D. Biol. Crystallogr. 58, 1948–1954 (2002).

    Article  Google Scholar 

  38. Emsley, P. & Cowtan, K. Coot: model-building tools for molecular graphics. Acta Crystallogr. D. Biol. Crystallogr. 60, 2126–2132 (2004).

    Article  Google Scholar 

  39. Collaborative Computational Project, Number 4. The CCP4 suite: programs for protein crystallography. Acta Crystallogr. D. Biol. Crystallogr. 50, 760–763 (1994).

  40. Winn, M. D., Murshudov, G. N. & Papiz, M. Z. Macromolecular TLS refinement in REFMAC at moderate resolutions. Methods Enzymol. 374, 300–321 (2003).

    Article  CAS  Google Scholar 

  41. Moineau, S., Durmaz, E., Pandian, S. & Klaenhammer, T. R. Differentiation of two abortive mechanisms by using monoclonal antibodies directed toward lactococcal bacteriophage capsid proteins. Appl. Environ. Microbiol. 59, 208–212 (1993).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank the staff of the BL19U1 beamline of the National Facility for Protein Science in Shanghai (NFPS) at Shanghai Synchrotron Radiation Facility for assistance in data collection. This work was supported by grants from the National Natural Science Foundation of China (grant nos. 31925002 to Shi Chen, 32125001 to L.W., and 31872627 and 32170030 to G.W.), the National Key Research and Development Program of China (grant nos. 2022YFA0912200 to L.W., 2022YFA0912500 to Shi Chen. and 2020YFA0907300 to G.W.) and the Shanghai Jiao Tong University Scientific and Technological Innovation Fund (to G.W.).

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Authors

Contributions

Shi Chen, G.W. and L.W. conceived the study and supervised the project. D.W., Y.T., Siwei Chen, Y.H. and X.C. performed the experiments. D.W., Y.T., Siwei Chen, Y.H., X.C., W.Z., Z.D., Z.L., L.W., G.W. and Shi Chen analysed the data. D.W., L.W., G.W. and Shi Chen wrote the manuscript.

Corresponding authors

Correspondence to Lianrong Wang, Geng Wu or Shi Chen.

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Nature Catalysis thanks Weixin Tang, Konstantin Severinov and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Extended data

Extended Data Fig. 1 SDS–PAGE gel and SEC-MALS analysis of the E.DndFGH complex.

a, Gel filtration profile of His-DndF, His-DndG, His-DndH and the DndFGH complex of B7A. The E.DndFGH complex was prepared by mixing His-DndF (64 μM), His-DndG (64 μM) and His-DndH (32 μM). b, A gel image of the SDS–PAGE analysis of eluted protein fractions from the size-exclusion chromatography. Results are representative of three independent experiments. c, No obvious DNA was observed in the eluted protein fractions by agarose gel electrophoresis. To exclude the involvement of DNA in the formation of the DndFGH complex, the mixture of DndF, DndG and DndH was treated with DNase I (0.033 U/µl) at 37 °C for 10 min. DNase I is capable of digesting DNA up to 5 μg under our experimental conditions. Results are representative of three independent experiments. d, SEC-MALS analysis shows that the E.DndFGH complex elutes with a molecular mass of 434.03 kDa, consistent with a theoretical value of 433.44 kDa when DndF, DndG and DndH, as shown in (a), assemble into a complex in a molar ratio of 2:2:1. The left and right axes represent the molecular weight and the light scattering detector reading, respectively. The black curve represents the calculated molecular weight. Results are representative of three independent experiments.

Source data

Extended Data Fig. 2 Nonspecific nicking activity of E.DndFGH.

Run-off sequencing of open circular pUC19 treated with DndFGH or Nt. BspQI. The peaks in the sequencing chromatogram dropped dramatically at the sequence-specific nicking site of Nt.BspQI. In contrast, no such sequencing peak drop was observed when DndFGH-nicked pUC19 DNA was used as a template despite the presence of the 5′-GAAC-3′/5′-GTTC-3′ motif (red underlined).

Extended Data Fig. 3 Structural comparison.

Structural superimposition showing the similarities between the DndHCTD structure (hot pink, PDB code: 7ES4) and VirB4CTD (cyan, PDB code: 4AG5), HerA (green/cyan, PDB code: 4D2I) and TrwBΔN70 (slate, PDB code: 1E9S).

Extended Data Fig. 4 Translocation assays.

a–c, Streptavidin displacement over time from biotinylated DNA (250 ng) ranging from 150 to 750 bp is shown in the presence of E.DndFGH (a), E.DndFGHK1354A (b) or E.DndFGHD1574A (c). The molar ratio between E.DndFGH and DNA is approx. 5:1. d, The stacked column chart shows the relative percentages of free DNA and streptavidin-bound DNA (SA DNA). The results were obtained by quantitation of the gels in panel (a). Values represent the mean ± SD of three independent streptavidin displacement experiments. e, The steady-state rate of ATPase hydrolysis as a function of the DNA length and DNA concentration. Concentration is plotted as micromolar-base pairs (μMbp). Values represent the mean ± SD from three biologically independent experiments. f, g, The trends are fit with the Michaelis–Menten equation, allowing for the extraction of the Km (f) and Vmax (g) parameters. Data represent the mean ± SD from three biologically independent experiments.

Source data

Extended Data Fig. 5 A schematic model of PT modification-modulated DndFGH defence.

a, DndA/IscS and DndBCDE proteins act as the modification component to confer PT modification at a subset of 5′-GAAC-3′/5′-GTTC-3′ sites in host DNA, generating 5′-GPSAAC-3′/5′-GPSTTC-3′. b, As the restriction component, the DndFGH complex undergoes conformational changes to generate DNA nicking and translocation activities. Furthermore, PTs in self-DNA suppress the DNA-stimulated ATP hydrolysis activity of the DndFGH complex and consequently impedes its translocation and nicking activities, thus preventing autoimmunity.

Extended Data Fig. 6 Self-vs-nonself discrimination of DndFGH in vitro.

When PT-modified (PT+) pUC19 and unmodified (PT) pACYC184 DNA were mixed at a 1:1 ratio and subjected to the nuclease digestion of E.DndFGH, PT+ pUC19 remained intact, whereas pACYC184 was specifically damaged. Without PT modification, PT pUC19 DNA is also susceptible to E.DndFGH. Results are representative of three independent experiments.

Source data

Supplementary information

Supplementary Information

Supplementary Tables 1 and 2 and Figs. 1–3.

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Supplementary Tables 3–5.

Source data

Source Data Fig. 1

Unprocessed plates, statistical source data.

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Source Data Extended Data Fig. 1

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Source Data Extended Data Fig. 4

Unprocessed gels, statistical source data.

Source Data Extended Data Fig. 6

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Wu, D., Tang, Y., Chen, S. et al. The functional coupling between restriction and DNA phosphorothioate modification systems underlying the DndFGH restriction complex. Nat Catal 5, 1131–1144 (2022). https://doi.org/10.1038/s41929-022-00884-2

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