Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Functional optimization of gene clusters by combinatorial design and assembly

Abstract

Large microbial gene clusters encode useful functions, including energy utilization and natural product biosynthesis, but genetic manipulation of such systems is slow, difficult and complicated by complex regulation. We exploit the modularity of a refactored Klebsiella oxytoca nitrogen fixation (nif) gene cluster (16 genes, 103 parts) to build genetic permutations that could not be achieved by starting from the wild-type cluster. Constraint-based combinatorial design and DNA assembly are used to build libraries of radically different cluster architectures by varying part choice, gene order, gene orientation and operon occupancy. We construct 84 variants of the nifUSVWZM operon, 145 variants of the nifHDKY operon, 155 variants of the nifHDKYENJ operon and 122 variants of the complete 16-gene pathway. The performance and behavior of these variants are characterized by nitrogenase assay and strand-specific RNA sequencing (RNA-seq), and the results are incorporated into subsequent design cycles. We have produced a fully synthetic cluster that recovers 57% of wild-type activity. Our approach allows the performance of genetic parts to be quantified simultaneously in hundreds of genetic contexts. This parallelized design-build-test-learn cycle, which can access previously unattainable regions of genetic space, should provide a useful, fast tool for genetic optimization and hypothesis testing.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Combinatorial design and construction of gene cluster libraries.
Figure 2: Screening results for the nif cluster optimization in K. oxytoca.
Figure 3: Transcriptomic analysis of the optimized refactored clusters and nifUSVWZM library.
Figure 4: Transfer of refactored nif clusters into E. coli MG1655.

Similar content being viewed by others

Accession codes

Primary accessions

Sequence Read Archive

References

  1. Czar, M.J., Anderson, J.C., Bader, J.S. & Peccoud, J. Gene synthesis demystified. Trends Biotechnol. 27, 63–72 (2009).

    Article  CAS  Google Scholar 

  2. Gibson, D.G. et al. Creation of a bacterial cell controlled by a chemically synthesized genome. Science 329, 52–56 (2010).

    Article  CAS  Google Scholar 

  3. Kröger, J.D. et al. The transcriptional landscape and small RNAs of Salmonella enterica serovar Typhimurium. Proc. Natl. Acad. Sci. USA 109, E1277–E1286 (2012).

    Article  Google Scholar 

  4. Arnold, W., Rump, A., Klipp, W., Priefer, U.B. & Pühler, A. Nucleotide sequence of a 24,206-base-pair DNA fragment carrying the entire nitrogen fixation gene cluster of Klebsiella pneumoniae. J. Mol. Biol. 203, 715–738 (1988).

    Article  CAS  Google Scholar 

  5. Chan, L.Y., Kosuri, S. & Endy, D. Refactoring bacteriophage T7. Mol. Sys. Biol. 1, 2005.0018 (2005).

    Google Scholar 

  6. Temme, K., Zhao, D. & Voigt, C.A. Refactoring the nitrogen fixation gene cluster from Klebsiella oxytoca. Proc. Natl. Acad. Sci. USA 109, 7085–7090 (2012).

    Article  Google Scholar 

  7. Temme, K., Hill, R., Segall-Shapiro, T.H., Moser, F. & Voigt, C.A. Modular control of multiple pathways using engineered orthogonal T7 polymerases. Nucleic Acids Res. 40, 8773–8781 (2012).

    Article  CAS  Google Scholar 

  8. Beatty, P.H. & Good, A.G. Future prospects for cereals that fix nitrogen. Science 333, 416–417 (2011).

    Article  CAS  Google Scholar 

  9. Arnold, W., Rump, A., Klipp, W., Priefer, U.B. & Pühler, A. Nucleotide sequence of a 24,206-base-pair DNA fragment carrying the entire nitrogen fixation gene cluster of Klebsiella pneumoniae. J. Mol. Biol. 203, 715–738 (1988).

    Article  CAS  Google Scholar 

  10. Eady, R.R., Issack, R., Kennedy, C., Postgate, J.R. & Ratcliffe, H.D. Nitrogenase synthesis in Klebsiella pneumonia: comparison of ammonium and oxygen regulation. J. Gen. Microbiol. 104, 277–285 (1978).

    Article  CAS  Google Scholar 

  11. Lowe, D.J. & Thorneley, R.N.F. The mechanism of Klebsiella pneumoniae nitrogenase action: pre-steady-state kinetics of H2 formation. Biochem. J. 224, 877–886 (1984).

    Article  CAS  Google Scholar 

  12. Dixon, R., Cheng, Q., Shen, G.F., Day, A. & Dowson-Day, M. Nif gene transfer and expression in chloroplasts: prospects and problems. Plant Soil 194, 193–203 (1997).

    Article  CAS  Google Scholar 

  13. Dukes, P., Lamken, E. & Wilson, R. Workshop report: Combinatorial design theory (Banff International Research Station meeting 08w5098) https://www.birs.ca/workshops/2008/08w5098/report08w5098.pdf (2008).

  14. Alper, H., Fischer, C., Nevoigt, E. & Stephanopoulos, G. Tuning genetic control through promoter engineering. Proc. Natl. Acad. Sci. USA 102, 12678–12683 (2005).

    Article  CAS  Google Scholar 

  15. Beynon, J., Cannon, M., Buchanan-Wollaston, V. & Cannon, F. The nif promoters of Klebsiella pneumonia have a characteristic primary structure. Cell 34, 665–671 (1983).

    Article  CAS  Google Scholar 

  16. Bilitchenko, L. et al. Eugene—a domain specific language for specifying and constraining synthetic biological parts, devices, and systems. PLoS ONE 6, e18882 (2011).

    Article  CAS  Google Scholar 

  17. Salis, H.M., Mirsky, E.A. & Voigt, C.A. Automated design of synthetic ribosome binding sites to control protein expression. Nat. Biotechnol. 27, 946–950 (2009).

    Article  CAS  Google Scholar 

  18. Davis, J.H., Rubin, A.J. & Sauer, R.T. Design, construction and characterization of a set of insulated bacterial promoters. Nucleic Acids Res. 39, 1131–1141 (2011).

    Article  CAS  Google Scholar 

  19. Crook, N.C., Freeman, E.S. & Alper, H.S. Re-engineering multicloning sites for function and convenience. Nucleic Acids Res. 39, e92 (2011).

    Article  CAS  Google Scholar 

  20. Weber, E., Engler, C., Gruetzner, R., Werner, S. & Marillonnet, S. A modular cloning system for standardized assembly of multigene constructs. PLoS ONE 6, e16765 (2011).

    Article  CAS  Google Scholar 

  21. Wang, X. et al. Using synthetic biology to distinguish and overcome regulatory and functional barriers related to nitrogen fixation. PLoS ONE 8, e68677 (2013).

    Article  CAS  Google Scholar 

  22. Cannon, F.C., Dixon, R.A. & Postgate, J.R. Derivation and properties of F-prime factors in Escherichia coli carrying nitrogen fixation genes from Klebsiella pneumoniae. J. Gen. Microbiol. 93, 111–125 (1976).

    Article  CAS  Google Scholar 

  23. Price, M.N., Huang, K.H., Arkin, A.P. & Alm, E.J. Operon formation is driven by co-regulation and not by horizontal gene transfer. Genome Res. 15, 809–819 (2005).

    Article  CAS  Google Scholar 

  24. Lim, H.N., Lee, Y. & Hussein, R. Fundamental relationship between operon organization and gene expression. Proc. Natl. Acad. Sci. USA 108, 10626–10631 (2011).

    Article  CAS  Google Scholar 

  25. Liang, L.W., Hussein, R., Block, D.H.S. & Lim, H.N. Minimal effect of gene clustering on expression in Escherichia coli. Genetics 193, 453–465 (2013).

    Article  CAS  Google Scholar 

  26. Endy, D., You, L., Yin, J. & Molineux, I. Computation, prediction, and experimental test of fitness for bacteriophage T7 mutants with permuted genomes. Proc. Natl. Acad. Sci. USA 97, 5375–5380 (2000).

    Article  CAS  Google Scholar 

  27. von Dassow, G., Meir, E., Munro, E.M. & Odell, G.M. The segment polarity network is a robust developmental module. Nature 406, 188–192 (2000).

    Article  CAS  Google Scholar 

  28. Hamilton, T.L. et al. Transcriptional profiling of nitrogen fixation in Azotobacter vinelandii. J. Bacteriol. 193, 4477–4486 (2011).

    Article  CAS  Google Scholar 

  29. Yan, Y. et al. Global transcriptional analysis of nitrogen fixation and ammonium repression in root-associated Pseudomonas stutzeri A1501. BMC Genomics 11, 11 (2010).

    Article  Google Scholar 

  30. Poza-Carrión, C., Jiménez-Vicente, E., Navarro-Rodríguez, M., Echavarri-Erasun, C. & Rubio, L.M. Kinetics of nif gene expression in a nitrogen-fixing bacterium. J. Bacteriol. 196, 595–603 (2014).

    Article  Google Scholar 

  31. Jeng, S.T., Gardner, J.F. & Gumport, R.I. Transcription termination by bacteriophage T7 RNA polymerase at rho-independent terminators. J. Biol. Chem. 265, 3823–3830 (1990).

    CAS  PubMed  Google Scholar 

  32. McAllister, W.T. & Morris, C. Utilization of bacteriophage T7 late promoters in recombinant plasmids during infection. J. Mol. Biol. 153, 527–544 (1981).

    Article  CAS  Google Scholar 

  33. Cardinale, S. & Arkin, A.P. Contextualizing context for synthetic biology–identifying causes of failure of synthetic biological systems. Biotechnol. J. 7, 856–866 (2012).

    Article  CAS  Google Scholar 

  34. Dixon, R.A. & Postgate, J.R. Genetic transfer of nitrogen fixation from Klebsiella pneumoniae to Escherichia coli. Nature 237, 102–103 (1972).

    Article  CAS  Google Scholar 

  35. Dixon, R. & Cannon, F. Construction of a P plasmid carrying nitrogen fixation genes from Klebsiella pneumoniae. Nature 260, 268–271 (1976).

    Article  CAS  Google Scholar 

  36. Moser, F. et al. Genetic circuit performance under conditions relevant for industrial bioreactors. ACS Synth. Biol. 1, 555–564 (2012).

    Article  CAS  Google Scholar 

  37. Gorochowski, T.E., van den Berg, E., Kerkman, R., Roubos, J.A. & Bovenberg, R.A.L. Using synthetic biological parts and microbioreactors to explore the protein expression characteristics of Escherichia coli. ACS Synth. Biol. 3, 129–139 (2014).

    Article  CAS  Google Scholar 

  38. Plackett, R.L. & Burman, J.P. The design of optimum multifactorial experiments. Biometrika 33, 305–325 (1946).

    Article  Google Scholar 

  39. May, O., Voigt, C.A. & Arnold, F.H. in Enzyme Catalysis in Organic Synthesis: A Comprehensive Handbook 2nd edn. (eds. Drauz, K. & Waldmann, H.) Ch. 4 (Wiley-VCH Verlag, 2002).

  40. Ran, L. et al. Genome erosion in a nitrogen-fixing vertically transmitted endosymbiotic multicellular cyanobacterium. PLoS ONE 5, e11486 (2010).

    Article  Google Scholar 

  41. Stucken, K. et al. The smallest known genomes of multicellular and toxic cyanobacteria: comparison, minimal gene sets for linked traits and the evolutionary implications. PLoS ONE 5, e9235 (2010).

    Article  Google Scholar 

  42. Endy, D., You, L., Yin, J. & Molineux, I.J. Computation, prediction, and experimental tests of fitness for bacteriophage T7 mutants with permuted genomes. Proc. Natl. Acad. Sci. USA 97, 5375–5380 (2000).

    Article  CAS  Google Scholar 

  43. Densmore, D., Kittleson, J.T., Bilitchenko, L., Liu, A. & Anderson, J.C. Rule based constraints for the construction of genetic devices. Proc. 2010 IEEE ISCAS, 10.1109/ISCAS.2010.5537540 (2010).

  44. Suh, M.H., Pulakat, L. & Gavini, N. Functional expression of the FeMo-cofacter-specific biosynthetic genes nifEN as a NifE-N fusion protein synthesizing unit in Azotobacter vinelandii. Biochem. Biophys. Res. Commun. 299, 233–240 (2002).

    Article  CAS  Google Scholar 

  45. Fischbach, M. & Voigt, C.A. Prokaryotic gene clusters: a rich toolbox for synthetic biology. Biotechnol. J. 5, 1277–1296 (2010).

    Article  CAS  Google Scholar 

  46. Stacy, G.S., Burris, R.H. & Evans, H.J. Biological Nitrogen Fixation (Chapman and Hall, 1992).

  47. Gibson, D.G. et al. Enzymatic assembly of DNA molecules up to several hundred kilobases. Nat. Methods 6, 343–345 (2009).

    Article  CAS  Google Scholar 

  48. Chen, Y.J. et al. Characterization of 582 natural and synthetic terminators and quantification of their design constraints. Nat. Methods 10, 659–664 (2013).

    Article  CAS  Google Scholar 

  49. Stewart, W.D., Fitzgerald, G.P. & Burris, R.H. In situ studies on nitrogen fixation with the acetylene reduction technique. Science 158, 536 (1967).

    Article  CAS  Google Scholar 

  50. Giannoukos, G. et al. Efficient and robust RNA-seq process for cultured bacteria and complex community transcriptomes. Genome Biol. 13, r23 (2012).

    Article  CAS  Google Scholar 

  51. Li, H. & Durbin, R. Fast and accurate short read alignment with Burrows-Wheeler transform. Bioinformatics 25, 1754–1760 (2009).

    Article  CAS  Google Scholar 

  52. Barnett, D.W., Garrison, E.K., Quinlan, A.R., Stromberg, M.P. & Marth, G.T. BamTools: a C++ API and toolkit for analyzing and managing BAM files. Bioinformatics 27, 1691–1692 (2011).

    Article  CAS  Google Scholar 

  53. Li, H. et al. 1000 Genome Project Data Processing Subgroup. The sequence alignment/map format and SAMtools. Bioinformatics 25, 2078–2079 (2009).

    Article  Google Scholar 

Download references

Acknowledgements

M.J.S., D.Z., J.C., R.N., D.B.G. and C.A.V. are supported by the US Defense Advanced Research Projects Agency (DARPA) Living Foundries grant HR0011-12-C-0067 and the US National Science Foundation Synthetic Biology Engineering Research Center (SynBERC) through grant SA5284-11210 and are also supported by the Institute for Collaborative Biotechnologies through contract W911NF-09-0001 from the US Army Research Office. The content of the information does not necessarily reflect the position or the policy of the US government, and no official endorsement should be inferred. S.B. and D.D. are supported by DARPA Living Foundries grant HR0011-12-C-0067. M.J.S. is an HHMI Fellow of the Damon Runyon Cancer Research Foundation, DRG-2129-12. Y.P. is supported by the Samsung Scholarship.

Author information

Authors and Affiliations

Authors

Contributions

M.J.S., D.Z. and C.A.V. conceived and designed the experiments and wrote the manuscript. M.J.S. performed the nifUSVWZM, monocistronic and RBS library construction and analysis. D.D. and S.B. performed the clustering analysis, wrote the design files and analyzed data. D.Z. constructed and analyzed the nifHDKY, nifENJ and complete cluster library. Y.P., D.B.G., M.B., G.G., R.N. and D.C. performed the RNA-seq experiments and analysis. L.B.A.W. and J.C. performed experiments.

Corresponding author

Correspondence to Christopher A Voigt.

Ethics declarations

Competing interests

S.B. and D.D. are co-founders of Lattice Automation, Inc., a company that produces biodesign automation software.

Supplementary information

Supplementary Text and Figures

Supplementary Figures 1–27, Supplementary Tables 1 and 2 and Supplementary Notes 1–11 (PDF 9314 kb)

Supplementary Data File 1.eug

Eugene file for nifUSVWZM libray design (XLS 28 kb)

Supplementary Data File 2.eug

Eugene file for newly identified rules for refactored nif cluster (XLS 42 kb)

Supplementary Data File 3.xlsx

Characterization data for nifUSVWZM library (XLSX 6348 kb)

Supplementary Data File 4.xlsx

Characterization data for nifHDKY, nifENJ, and full cluster libraries (XLSX 33 kb)

Supplementary Data File 5.xlsx

Characterization data for 16-gene monocistronic library (XLSX 69 kb)

Supplementary Data File 6.xlsx

Characterization data for 16-gene RBS swapping library (XLSX 42 kb)

Supplementary Data File 7.eug

Eugene file for 16-gene monocistronic library (XLS 27 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Smanski, M., Bhatia, S., Zhao, D. et al. Functional optimization of gene clusters by combinatorial design and assembly. Nat Biotechnol 32, 1241–1249 (2014). https://doi.org/10.1038/nbt.3063

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nbt.3063

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing