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DNA uptake during bacterial transformation
Nature Reviews Microbiologyvolume 2, pages241–249 (2004)Cite this article
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Key Points
Genetic competence refers to the ability of some bacteria to undergo transformation — to take up exogenous DNA and incorporate it stably into their own genome.
Naturally transformable organisms express specialized proteins that function in DNA uptake and processing. These proteins are usually conserved among the competent bacteria, both Gram-positive and Gram-negative.
Among the proteins that are involved in DNA uptake, a subset is related to components of the type IV pilus and type II secretion systems. In piliated Gram-negative organisms, these proteins are involved in both pilus formation and DNA uptake, leading to a correlation between these two phenotypes.
The function of this group of proteins is to bring DNA from the surface, across the outer membrane, peptidoglycan layer and periplasmic space (in Gram-negatives), or across the cell wall (in Gram-positives), to the cytoplasmic membrane.
By contrast,Helicobacter pylori uses proteins that are related to components of the type IV secretion and conjugation systems to bring DNA to the cytoplasmic membrane.
A translocation complex mediates the transport of DNA across the cytoplasmic membrane. The proteins in this complex are: a DNA receptor, a polytopic membrane protein that can form a channel and an ATP-binding protein. These components show characteristics of elements from ABC transporter systems.
Abstract
Naturally competent bacteria are able to take up exogenous DNA and undergo genetic transformation. The transport of DNA from the extracellular milieu into the cytoplasm is a complex process, and requires proteins that are related to those involved in the assembly of type IV pili and type II secretion systems, as well as a DNA translocase complex at the cytoplasmic membrane. Here, we will review the current knowledge of DNA transport during transformation.
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References
Lorenz, M. G. & Wackernagel, W. Bacterial gene transfer by natural genetic transformation in the environment.Microbiol. Rev.58, 563–602 (1994).
MacFadyen, L. P. et al. Competence development byHaemophilus influenzae is regulated by the availability of nucleic acid precursors.Mol. Microbiol.40, 700–707 (2001).
Claverys, J. P. & Havarstein, L. S. Extracellular-peptide control of competence for genetic transformation inStreptococcus pneumoniae.Front. Biosci.7, d1798–d1814 (2002).
Hamoen, L. W., Venema, G. & Kuipers, O. P. Controlling competence inBacillus subtilis: shared use of regulators.Microbiology149, 9–17 (2003).
Claverys, J. P. & Martin, B. Bacterial 'competence' genes: signatures of active transformation, or only remnants?Trends Microbiol.11, 161–165 (2003).
Inamine, G. S. & Dubnau, D. ComEA, aBacillus subtilis integral membrane protein required for genetic transformation, is needed for both DNA binding and transport.J. Bacteriol.177, 3045–3051 (1995).
Berge, M., Moscoso, M., Prudhomme, M., Martin, B. & Claverys, J. P. Uptake of transforming DNA in Gram-positive bacteria: a view fromStreptococcus pneumoniae.Mol. Microbiol.45, 411–421 (2002).
Strauss, N. Configuration of transforming deoxyribonucleic acid during entry intoBacillus subtilis.J. Bacteriol.89, 288–293 (1965).
Provvedi, R., Chen, I. & Dubnau, D. NucA is required for DNA cleavage during transformation ofBacillus subtilis.Mol. Microbiol.40, 634–644 (2001).
Lacks, S. & Greenberg, B. Single-strand breakage on binding of DNA to cells in the genetic transformation ofDiplococcus pneumoniae.J. Mol. Biol.101, 255–275 (1976).
Morrison, D. A. & Guild, W. R. Breakage prior to entry of donor DNA in pneumococcus transformation.Biochim. Biophys. Acta.299, 545–556 (1973).
Sisco, K. L. & Smith, H. O. Sequence-specific DNA uptake inHaemophilus transformation.Proc. Natl Acad. Sci. USA76, 972–976 (1979).
Goodman, S. D. & Scocca, J. J. Identification and arrangement of the DNA sequence recognized in specific transformation ofNeisseria gonorrhoeae.Proc. Natl Acad. Sci. USA85, 6982–6986 (1988).
Elkins, C., Thomas, C. E., Seifert, H. S. & Sparling, P. F. Species-specific uptake of DNA by gonococci is mediated by a 10-base-pair sequence.J. Bacteriol.173, 3911–3913 (1991).
Danner, D. B., Deich, R. A., Sisco, K. L. & Smith, H. O. An eleven-base-pair sequence determines the specificity of DNA uptake inHaemophilus transformation.Gene11, 311–318 (1980).
Fitzmaurice, W. P., Benjamin, R. C., Huang, P. C. & Scocca, J. J. Characterization of recognition sites on bacteriophage HP1c1 DNA which interact with the DNA uptake system ofHaemophilus influenzae.Gene31, 187–196 (1984).
Wang, Y., Goodman, S. D., Redfield, R. J. & Chen, C. Natural transformation and DNA uptake signal sequences inActinobacillus actinomycetemcomitans.J. Bacteriol.184, 3442–3449 (2002).
Smith, H. O., Tomb, J. F., Dougherty, B. A., Fleischmann, R. D. & Venter, J. C. Frequency and distribution of DNA uptake signal sequences in theHaemophilus influenzae Rd genome.Science269, 538–540 (1995).
Parkhill, J. et al. Complete DNA sequence of a serogroup A strain ofNeisseria meningitidis Z2491.Nature404, 502–506 (2000).
Tettelin, H. et al. Complete genome sequence ofNeisseria meningitidis serogroup B strain MC58.Science287, 1809–1815 (2000).
Aas, F. E. et al. Competence for natural transformation inNeisseria gonorrhoeae: components of DNA binding and uptake linked to type IV pilus expression.Mol. Microbiol.46, 749–760 (2002).
Aas, F. E., Lovold, C. & Koomey, M. An inhibitor of DNA binding and uptake events dictates the proficiency of genetic transformation inNeisseria gonorrhoeae: mechanism of action and links to type IV pilus expression.Mol. Microbiol.46, 1441–1450 (2002).References 21 and 22 show that expression of two minor pilins can modulate the ability ofNeisseria gonorrhoeae to bind and take up DNA; the role of PilT, the traffic NTPase responsible for pilus retraction and twitching motility, is also investigated.
Kahn, M. E., Barany, F. & Smith, H. O. Transformasomes: specialized membranous structures that protect DNA duringHaemophilus transformation.Proc. Natl Acad. Sci. USA80, 6927–6931 (1983).
Drake, S. L., Sandstedt, S. A. & Koomey, M. PilP, a pilus biogenesis lipoprotein inNeisseria gonorrhoeae, affects expression of PilQ as a high-molecular-mass multimer.Mol. Microbiol.23, 657–668 (1997).
Nouwen, N. et al. Secretin PulD: association with pilot PulS, structure, and ion-conducting channel formation.Proc. Natl Acad. Sci. USA96, 8173–8177 (1999).
Collins, R. F., Davidsen, L., Derrick, J. P., Ford, R. C. & Tonjum, T. Analysis of the PilQ secretin fromNeisseria meningitidis by transmission electron microscopy reveals a dodecameric quaternary structure.J. Bacteriol.183, 3825–3832 (2001).
Nouwen, N., Stahlberg, H., Pugsley, A. P. & Engel, A. Domain structure of secretin PulD revealed by limited proteolysis and electron microscopy.EMBO J.19, 2229–2236 (2000).
Opalka, N. et al. Structure of the filamentous phage pIV multimer by cryo-electron microscopy.J. Mol. Biol.325, 461–470 (2003).
Marciano, D. K., Russel, M. & Simon, S. M. An aqueous channel for filamentous phage export.Science284, 1516–1519 (1999).
Drake, S. L. & Koomey, M. The product of thepilQ gene is essential for the biogenesis of type IV pili inNeisseria gonorrhoeae.Mol. Microbiol.18, 975–986 (1995).
Parge, H. E. et al. Structure of the fibre-forming protein pilin at 2. 6 Å resolution.Nature378, 32–38 (1995).
Merz, A. J., So, M. & Sheetz, M. P. Pilus retraction powers bacterial twitching motility.Nature407, 98–102 (2000).
Skerker, J. M. & Berg, H. C. Direct observation of extension and retraction of type IV pili.Proc. Natl Acad. Sci. USA98, 6901–6904 (2001).
Mattick, J. S. Type IV pili and twitching motility.Annu. Rev. Microbiol.56, 289–314 (2002).
LaPointe, C. F. & Taylor, R. K. The type 4 prepilin peptidases comprise a novel family of aspartic acid proteases.J. Biol. Chem.275, 1502–1510 (2000).
Nunn, D. Bacterial type II protein export and pilus biogenesis: more than just homologies?Trends Cell Biol.9, 402–408 (1999).
Keizer, D. W. et al. Structure of a pilin monomer fromPseudomonas aeruginosa: implications for the assembly of pili.J. Biol. Chem.276, 24186–24193 (2001).
Tonjum, T. & Koomey, M. The pilus colonization factor of pathogenic neisserial species: organelle biogenesis and structure/function relationships — a review.Gene192, 155–163 (1997).
Wolfgang, M., van Putten, J. P., Hayes, S. F., Dorward, D. & Koomey, M. Components and dynamics of fiber formation define a ubiquitous biogenesis pathway for bacterial pili.EMBO J.19, 6408–6418 (2000).
Wolfgang, M. et al. PiIT mutations lead to simultaneous defects in competence for natural transformation and twitching motility in piliatedNeisseria gonorrhoeae.Mol. Microbiol.29, 321–330 (1998).
Russel, M. Macromolecular assembly and secretion across the bacterial cell envelope: type II protein secretion systems.J. Mol. Biol.279, 485–499 (1998).
Sandkvist, M. Biology of type II secretion.Mol. Microbiol.40, 271–283 (2001).
Pugsley, A. P. The complete general secretory pathway in Gram-negative bacteria.Microbiol. Rev.57, 50–108 (1993).
Sauvonnet, N., Vignon, G., Pugsley, A. P. & Gounon, P. Pilus formation and protein secretion by the same machinery inEscherichia coli.EMBO J.19, 2221–2228 (2000).
Durand, E. et al. Type II protein secretion inPseudomonas aeruginosa: the pseudopilus is a multifibrillar and adhesive structure.J. Bacteriol.185, 2749–2758 (2003).References 44 and 45 confirmed the long-held suspicion that the pseudopilins from type II secretion systems can be assembled by the other components of the secreton into a higher-order structure, the pseudopilus; whether this finding applies to the pseudopilins involved in competence remains to be determined.
Vignon, G. et al. Type IV-like pili formed by the type II secreton: specificity, composition, bundling, polar localization, and surface presentation of peptides.J. Bacteriol.185, 3416–3428 (2003).
Sparling, P. F. Genetic transformation ofNeisseria gonorrhoeae to streptomycin resistance.J. Bacteriol.92, 1364–1371 (1966).
Stone, B. J. & Kwaik, Y. A. Natural competence for DNA transformation byLegionella pneumophila and its association with expression of type IV pili.J. Bacteriol.181, 1395–1402 (1999).
Graupner, S. et al. Type IV pilus genespilA andpilC ofPseudomonas stutzeri are required for natural genetic transformation, andpilA can be replaced by corresponding genes from nontransformable species.J. Bacteriol.182, 2184–2190 (2000).
Yoshihara, S. et al. Mutational analysis of genes involved in pilus structure, motility and transformation competency in the unicellular motile cyanobacteriumSynechocystis sp. PCC 6803.Plant Cell Physiol.42, 63–73 (2001).
Kennan, R. M., Dhungyel, O. P., Whittington, R. J., Egerton, J. R. & Rood, J. I. The type IV fimbrial subunit gene (fimA) ofDichelobacter nodosus is essential for virulence, protease secretion, and natural competence.J. Bacteriol.183, 4451–4458 (2001).
Mathis, L. S. & Scocca, J. J. On the role of pili in transformation ofNeisseria gonorrhoeae.J. Gen. Microbiol.130, 3165–3173 (1984).
Forest, K. T. & Tainer, J. A. Type-4 pilus-structure: outside to inside and top to bottom — a minireview.Gene192, 165–169 (1997).
Rudel, T. et al. Role of pili and the phase-variable PilC protein in natural competence for transformation ofNeisseria gonorrhoeae.Proc. Natl Acad. Sci. USA92, 7986–7990 (1995).
Gibbs, C. P. et al. Reassortment of pilin genes inNeisseria gonorrhoeae occurs by two distinct mechanisms.Nature338, 651–652 (1989).
Long, C. D., Tobiason, D. M., Lazio, M. P., Kline, K. A. & Seifert, H. S. Low-level pilin expression allows for substantial DNA transformation competence inNeisseria gonorrhoeae.Infect. Immun.71, 6279–6291 (2003).
Chen, I. & Dubnau, D. DNA transport during transformation.Front. Biosci.8, s544–s556 (2003).
Wolfgang, M., van Putten, J. P. Hayes, S. F. & Koomey, M. ThecomP locus ofNeisseria gonorrhoeae encodes a type IV prepilin that is dispensable for pilus biogenesis but essential for natural transformation.Mol. Microbiol.31, 1345–1357 (1999).
Friedrich, A., Rumszauer, J., Henne, A. & Averhoff, B. Pilin-like proteins in the extremely thermophilic bacteriumThermus thermophilus HB27: implication in competence for natural transformation and links to type IV pilus biogenesis.Appl. Environ. Microbiol.69, 3695–3700 (2003).
Porstendorfer, D., Drotschmann, U. & Averhoff, B. A novel competence gene,comP, is essential for natural transformation ofAcinetobacter.Appl. Environ. Microbiol.63, 4150–4157 (1997).
Graupner, S. & Wackernagel, W.Pseudomonas stutzeri has two closely relatedpilA genes (type IV pilus structural protein) with opposite influences on natural genetic transformation.J. Bacteriol.183, 2359–2366 (2001).
Dubnau, D. & Provvedi, R. Internalizing DNA.Res. Microbiol.151, 475–480 (2000).
Meima, R. et al. ThebdbDC operon ofBacillus subtilis encodes thiol-disulfide oxidoreductases required for competence development.J. Biol. Chem.277, 6994–7001 (2002).
Provvedi, R. & Dubnau, D. ComEA is a DNA receptor for transformation of competentBacillus subtilis.Mol. Microbiol.31, 271–280 (1999).The authors show that ComEA, a conserved competence protein required for both DNA binding and uptake, is itself a non-sequence-specific double-strand-DNA-binding protein, acting as a cell-surface DNA receptor.
Graupner, S., Weger, N., Sohni, M. & Wackernagel, W. Requirement of novel competence genespilT andpilU ofPseudomonas stutzeri for natural transformation and suppression ofpilT deficiency by a hexahistidine tag on the type IV pilus protein PilAI.J. Bacteriol.183, 4694–4701 (2001).
van Nieuwenhoven, M. H., Hellingwerf, K. J., Venema, G. & Konings, W. N. Role of proton motive force in genetic transformation ofBacillus subtilis.J. Bacteriol.151, 771–776 (1982).
Wolfgang, M., Park, H. S., Hayes, S. F., van Putten, J. P. & Koomey, M. Suppression of an absolute defect in type IV pilus biogenesis by loss-of-function mutations inpilT, a twitching motility gene inNeisseria gonorrhoeae.Proc. Natl Acad. Sci. USA95, 14973–14978 (1998).
Saier, M. H. Jr. A functional-phylogenetic classification system for transmembrane solute transporters.Microbiol. Mol. Biol. Rev.64, 354–411 (2000).
van der Heide, T. & Poolman, B. ABC transporters: one, two or four extracytoplasmic substrate-binding sites?EMBO Rep.3, 938–943 (2002).
Chen, I. & Gotschlich, E. C. ComE, a competence protein fromNeisseria gonorrhoeae with DNA-binding activity.J. Bacteriol.183, 3160–3168 (2001).
Friedrich, A., Hartsch, T. & Averhoff, B. Natural transformation in mesophilic and thermophilic bacteria: identification and characterization of novel, closely related competence genes inAcinetobacter sp. strain BD413 andThermus thermophilus HB27.Appl. Environ. Microbiol.67, 3140–3148 (2001).
Dubnau, D. DNA uptake in bacteria.Annu. Rev. Microbiol.53, 217–244 (1999).
Facius, D. & Meyer, T. F. A novel determinant (comA) essential for natural transformation competence inNeisseria gonorrhoeae.Mol. Microbiol.10, 699–712 (1993).
Graupner, S. & Wackernagel, W. Identification and characterization of novel competence genescomA andexbB involved in natural genetic transformation ofPseudomonas stutzeri.Res. Microbiol.152, 451–460 (2001).
Facius, D., Fussenegger, M. & Meyer, T. F. Sequential action of factors involved in natural competence for transformation ofNeisseria gonorrhoeae.FEMS Microbiol. Lett.137, 159–164 (1996).
Barany, F., Kahn, M. E. & Smith, H. O. Directional transport and integration of donor DNA inHaemophilus influenzae transformation.Proc. Natl Acad. Sci. USA80, 7274–7278 (1983).
Chaussee, M. S. & Hill, S. A. Formation of single-stranded DNA during DNA transformation ofNeisseria gonorrhoeae.J. Bacteriol.180, 5117–5122 (1998).
Berge, M., Mortier-Barriere, I., Martin, B. & Claverys, J. P. Transformation ofStreptococcus pneumoniae relies on DprA- and RecA-dependent protection of incoming DNA single strands.Mol. Microbiol.50, 527–536 (2003).
Nedenskov-Sorensen, P., Bukholm, G. & Bovre, K. Natural competence for genetic transformation inCampylobacter pylori.J. Infect. Dis.161, 365–366 (1990).
Saunders, N. J., Peden, J. F. & Moxon, E. R. Absence inHelicobacter pylori of an uptake sequence for enhancing uptake of homospecific DNA during transformation.Microbiology145, 3523–3528 (1999).
Israel, D. A., Lou, A. S. & Blaser, M. J. Characteristics ofHelicobacter pylori natural transformation.FEMS Microbiol. Lett.186, 275–280 (2000).
Bart, A., Smeets, L. C. & Kusters, J. G. DNA uptake sequences inHelicobacter pylori.Microbiology146, 1255–1256 (2000).
Christie, P. J. Type IV secretion: intercellular transfer of macromolecules by systems ancestrally related to conjugation machines.Mol. Microbiol.40, 294–305 (2001).
Hofreuter, D., Odenbreit, S., Henke, G. & Haas, R. Natural competence for DNA transformation inHelicobacter pylori: identification and genetic characterization of thecomB locus.Mol. Microbiol.28, 1027–1038 (1998).
Hofreuter, D., Odenbreit, S. & Haas, R. Natural transformation competence inHelicobacter pylori is mediated by the basic components of a type IV secretion system.Mol. Microbiol.41, 379–391 (2001).References 84 and 85 show that transformation inHelicobacter pylori is mediated by proteins related to components of type IV secretion systems, in contrast to other competence systems, which use type-II-secretion-related proteins.
Hofreuter, D., Karnholz, A. & Haas, R. Topology and membrane interaction ofHelicobacter pylori ComB proteins involved in natural transformation competence.Int. J. Med. Microbiol.293, 153–165 (2003).
Yeh, Y. C., Lin, T. L., Chang, K. C. & Wang, J. T. Characterization of a ComE3 homologue essential for DNA transformation inHelicobacter pylori.Infect. Immun.71, 5427–5431 (2003).
Bacon, D. J. et al. Involvement of a plasmid in virulence ofCampylobacter jejuni 81-176.Infect. Immun68, 4384–4390 (2000).
Wiesner, R. S., Hendrixson, D. R. & DiRita, V. J. Natural transformation ofCampylobacter jejuni requires components of a type II secretion system.J. Bacteriol.185, 5408–5418 (2003).
Redfield, R. J. Genes for breakfast: the have-your-cake-and-eat-it-too of bacterial transformation.J. Hered.84, 400–404 (1993).
Redfield, R. J. Do bacteria have sex?Nature Rev. Genet.2, 634–639 (2001).
Steinmoen, H., Teigen, A. & Havarstein, L. S. Competence-induced cells ofStreptococcus pneumoniae lyse competence-deficient cells of the same strain during cocultivation.J. Bacteriol.185, 7176–7183 (2003).
Steinmoen, H., Knutsen, E. & Havarstein, L. S. Induction of natural competence inStreptococcus pneumoniae triggers lysis and DNA release from a subfraction of the cell population.Proc. Natl Acad. Sci. USA99, 7681–7686 (2002).
Dillard, J. P. & Seifert, H. S. A variable genetic island specific forNeisseria gonorrhoeae is involved in providing DNA for natural transformation and is found more often in disseminated infection isolates.Mol. Microbiol.41, 263–277 (2001).
Griffith, F. Significance of Pneumococcal types.J. Hyg.27, 113 (1928).
Avery, O. T., MacLeod, C. M. & McCarthy, M. Studies on the chemical nature of the substance inducing transformation of pneumococcal types. I. Induction of transformation by a deoxyribonucleic acid fraction isolated from pneumococcus type III.J. Exp. Med.79, 137 (1944).A seminal paper in the history of modern genetics, demonstrating that the 'transforming principle' is DNA.
Dougherty, B. A. & Smith, H. O. Identification ofHaemophilus influenzae Rd transformation genes using cassette mutagenesis.Microbiology145, 401–409 (1999).
Friedrich, A., Prust, C., Hartsch, T., Henne, A. & Averhoff, B. Molecular analyses of the natural transformation machinery and identification of pilus structures in the extremely thermophilic bacteriumThermus thermophilus strain HB27.Appl. Environ. Microbiol.68, 745–755 (2002).
Koomey, M. Competence for natural transformation inNeisseria gonorrhoeae: a model system for studies of horizontal gene transfer.APMIS Suppl.84, 56–61 (1998).
Pestova, E. V. & Morrison, D. A. Isolation and characterization of threeStreptococcus pneumoniae transformation-specific loci by use of alacZ reporter insertion vector.J. Bacteriol.180, 2701–2710 (1998).
Winther-Larsen, H. C. et al.Neisseria gonorrhoeae PilV, a type IV pilus-associated protein essential to human epithelial cell adherence.Proc. Natl Acad. Sci. USA98, 15276–15281 (2001).
Campbell, E. A., Choi, S. Y. & Masure, H. R. A competence regulon inStreptococcus pneumoniae revealed by genomic analysis.Mol. Microbiol.27, 929–939 (1998).
Smeets, L. C. & Kusters, J. G. Natural transformation inHelicobacter pylori: DNA transport in an unexpected way.Trends Microbiol.10, 159–162 (2002).
Acknowledgements
We thank members of our laboratory for helpful discussions and L. Mindich and B. Mulder for comments on the manuscript. We apologize to investigators whose work was not mentioned due to space constraints. The work cited from our lab was supported by NIH grants.
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Inês Chen & David Dubnau
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Chen, I., Dubnau, D. DNA uptake during bacterial transformation.Nat Rev Microbiol2, 241–249 (2004). https://doi.org/10.1038/nrmicro844
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