Skip to main content
NCBI home page
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1996 Feb;178(4):1207–1212. doi: 10.1128/jb.178.4.1207-1212.1996

VirE1 protein mediates export of the single-stranded DNA-binding protein VirE2 from Agrobacterium tumefaciens into plant cells.

C Sundberg 1, L Meek 1, K Carroll 1, A Das 1, W Ream 1
PMCID: PMC177787  PMID: 8576060

Abstract

Agrobacterium tumefaciens transfers single-stranded DNAs (T strands) into plant cells. VirE1 and VirE2, which is a single-stranded DNA binding protein, are important for tumorigenesis. We show that T strands and VirE2 can enter plant cells independently and that export of VirE2, but not of T strands, depends on VirE1.

Full Text

The Full Text of this article is available as a PDF (540.9 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Achtman M., Manning P. A., Edelbluth C., Herrlich P. Export without proteolytic processing of inner and outer membrane proteins encoded by F sex factor tra cistrons in Escherichia coli minicells. Proc Natl Acad Sci U S A. 1979 Oct;76(10):4837–4841. doi: 10.1073/pnas.76.10.4837. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Akiyoshi D. E., Klee H., Amasino R. M., Nester E. W., Gordon M. P. T-DNA of Agrobacterium tumefaciens encodes an enzyme of cytokinin biosynthesis. Proc Natl Acad Sci U S A. 1984 Oct;81(19):5994–5998. doi: 10.1073/pnas.81.19.5994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Albright L. M., Yanofsky M. F., Leroux B., Ma D. Q., Nester E. W. Processing of the T-DNA of Agrobacterium tumefaciens generates border nicks and linear, single-stranded T-DNA. J Bacteriol. 1987 Mar;169(3):1046–1055. doi: 10.1128/jb.169.3.1046-1055.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Barry G. F., Rogers S. G., Fraley R. T., Brand L. Identification of a cloned cytokinin biosynthetic gene. Proc Natl Acad Sci U S A. 1984 Aug;81(15):4776–4780. doi: 10.1073/pnas.81.15.4776. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Binns A. N., Beaupré C. E., Dale E. M. Inhibition of VirB-mediated transfer of diverse substrates from Agrobacterium tumefaciens by the IncQ plasmid RSF1010. J Bacteriol. 1995 Sep;177(17):4890–4899. doi: 10.1128/jb.177.17.4890-4899.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
  7. Chilton M. D., Drummond M. H., Merio D. J., Sciaky D., Montoya A. L., Gordon M. P., Nester E. W. Stable incorporation of plasmid DNA into higher plant cells: the molecular basis of crown gall tumorigenesis. Cell. 1977 Jun;11(2):263–271. doi: 10.1016/0092-8674(77)90043-5. [DOI] [PubMed] [Google Scholar]
  8. Chilton M. D., Saiki R. K., Yadav N., Gordon M. P., Quetier F. T-DNA from Agrobacterium Ti plasmid is in the nuclear DNA fraction of crown gall tumor cells. Proc Natl Acad Sci U S A. 1980 Jul;77(7):4060–4064. doi: 10.1073/pnas.77.7.4060. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Christie P. J., Ward J. E., Jr, Gordon M. P., Nester E. W. A gene required for transfer of T-DNA to plants encodes an ATPase with autophosphorylating activity. Proc Natl Acad Sci U S A. 1989 Dec;86(24):9677–9681. doi: 10.1073/pnas.86.24.9677. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Citovsky V., DE Vos G., Zambryski P. Single-Stranded DNA Binding Protein Encoded by the virE Locus of Agrobacterium tumefaciens. Science. 1988 Apr 22;240(4851):501–504. doi: 10.1126/science.240.4851.501. [DOI] [PubMed] [Google Scholar]
  11. Citovsky V., Wong M. L., Zambryski P. Cooperative interaction of Agrobacterium VirE2 protein with single-stranded DNA: implications for the T-DNA transfer process. Proc Natl Acad Sci U S A. 1989 Feb;86(4):1193–1197. doi: 10.1073/pnas.86.4.1193. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Citovsky V., Zupan J., Warnick D., Zambryski P. Nuclear localization of Agrobacterium VirE2 protein in plant cells. Science. 1992 Jun 26;256(5065):1802–1805. doi: 10.1126/science.1615325. [DOI] [PubMed] [Google Scholar]
  13. Covacci A., Rappuoli R. Pertussis toxin export requires accessory genes located downstream from the pertussis toxin operon. Mol Microbiol. 1993 May;8(3):429–434. doi: 10.1111/j.1365-2958.1993.tb01587.x. [DOI] [PubMed] [Google Scholar]
  14. Das A. Agrobacterium tumefaciens virE operon encodes a single-stranded DNA-binding protein. Proc Natl Acad Sci U S A. 1988 May;85(9):2909–2913. doi: 10.1073/pnas.85.9.2909. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Dash P. K., Traxler B. A., Panicker M. M., Hackney D. D., Minkley E. G., Jr Biochemical characterization of Escherichia coli DNA helicase I. Mol Microbiol. 1992 May;6(9):1163–1172. doi: 10.1111/j.1365-2958.1992.tb01555.x. [DOI] [PubMed] [Google Scholar]
  16. Di Laurenzio L., Frost L. S., Paranchych W. The TraM protein of the conjugative plasmid F binds to the origin of transfer of the F and ColE1 plasmids. Mol Microbiol. 1992 Oct;6(20):2951–2959. doi: 10.1111/j.1365-2958.1992.tb01754.x. [DOI] [PubMed] [Google Scholar]
  17. Ditta G., Schmidhauser T., Yakobson E., Lu P., Liang X. W., Finlay D. R., Guiney D., Helinski D. R. Plasmids related to the broad host range vector, pRK290, useful for gene cloning and for monitoring gene expression. Plasmid. 1985 Mar;13(2):149–153. doi: 10.1016/0147-619x(85)90068-x. [DOI] [PubMed] [Google Scholar]
  18. Dreiseikelmann B. Translocation of DNA across bacterial membranes. Microbiol Rev. 1994 Sep;58(3):293–316. doi: 10.1128/mr.58.3.293-316.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Dürrenberger F., Crameri A., Hohn B., Koukolíková-Nicola Z. Covalently bound VirD2 protein of Agrobacterium tumefaciens protects the T-DNA from exonucleolytic degradation. Proc Natl Acad Sci U S A. 1989 Dec;86(23):9154–9158. doi: 10.1073/pnas.86.23.9154. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Engström P., Zambryski P., Van Montagu M., Stachel S. Characterization of Agrobacterium tumefaciens virulence proteins induced by the plant factor acetosyringone. J Mol Biol. 1987 Oct 20;197(4):635–645. doi: 10.1016/0022-2836(87)90470-0. [DOI] [PubMed] [Google Scholar]
  21. Garfinkel D. J., Nester E. W. Agrobacterium tumefaciens mutants affected in crown gall tumorigenesis and octopine catabolism. J Bacteriol. 1980 Nov;144(2):732–743. doi: 10.1128/jb.144.2.732-743.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Garfinkel D. J., Simpson R. B., Ream L. W., White F. F., Gordon M. P., Nester E. W. Genetic analysis of crown gall: fine structure map of the T-DNA by site-directed mutagenesis. Cell. 1981 Nov;27(1 Pt 2):143–153. doi: 10.1016/0092-8674(81)90368-8. [DOI] [PubMed] [Google Scholar]
  23. Gietl C., Koukolíková-Nicola Z., Hohn B. Mobilization of T-DNA from Agrobacterium to plant cells involves a protein that binds single-stranded DNA. Proc Natl Acad Sci U S A. 1987 Dec;84(24):9006–9010. doi: 10.1073/pnas.84.24.9006. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Herrera-Estrella A., Chen Z. M., Van Montagu M., Wang K. VirD proteins of Agrobacterium tumefaciens are required for the formation of a covalent DNA--protein complex at the 5' terminus of T-strand molecules. EMBO J. 1988 Dec 20;7(13):4055–4062. doi: 10.1002/j.1460-2075.1988.tb03299.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Herrera-Estrella A., Van Montagu M., Wang K. A bacterial peptide acting as a plant nuclear targeting signal: the amino-terminal portion of Agrobacterium VirD2 protein directs a beta-galactosidase fusion protein into tobacco nuclei. Proc Natl Acad Sci U S A. 1990 Dec;87(24):9534–9537. doi: 10.1073/pnas.87.24.9534. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Howard E. A., Winsor B. A., De Vos G., Zambryski P. Activation of the T-DNA transfer process in Agrobacterium results in the generation of a T-strand-protein complex: Tight association of VirD2 with the 5' ends of T-strands. Proc Natl Acad Sci U S A. 1989 Jun;86(11):4017–4021. doi: 10.1073/pnas.86.11.4017. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Howard E. A., Zupan J. R., Citovsky V., Zambryski P. C. The VirD2 protein of A. tumefaciens contains a C-terminal bipartite nuclear localization signal: implications for nuclear uptake of DNA in plant cells. Cell. 1992 Jan 10;68(1):109–118. doi: 10.1016/0092-8674(92)90210-4. [DOI] [PubMed] [Google Scholar]
  28. Jayaswal R. K., Veluthambi K., Gelvin S. B., Slightom J. L. Double-stranded cleavage of T-DNA and generation of single-stranded T-DNA molecules in Escherichia coli by a virD-encoded border-specific endonuclease from Agrobacterium tumefaciens. J Bacteriol. 1987 Nov;169(11):5035–5045. doi: 10.1128/jb.169.11.5035-5045.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Kuldau G. A., De Vos G., Owen J., McCaffrey G., Zambryski P. The virB operon of Agrobacterium tumefaciens pTiC58 encodes 11 open reading frames. Mol Gen Genet. 1990 Apr;221(2):256–266. doi: 10.1007/BF00261729. [DOI] [PubMed] [Google Scholar]
  30. Lessl M., Balzer D., Pansegrau W., Lanka E. Sequence similarities between the RP4 Tra2 and the Ti VirB region strongly support the conjugation model for T-DNA transfer. J Biol Chem. 1992 Oct 5;267(28):20471–20480. [PubMed] [Google Scholar]
  31. McBride K. E., Knauf V. C. Genetic analysis of the virE operon of the Agrobacterium Ti plasmid pTiA6. J Bacteriol. 1988 Apr;170(4):1430–1437. doi: 10.1128/jb.170.4.1430-1437.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Okamoto S., Toyoda-Yamamoto A., Ito K., Takebe I., Machida Y. Localization and orientation of the VirD4 protein of Agrobacterium tumefaciens in the cell membrane. Mol Gen Genet. 1991 Aug;228(1-2):24–32. doi: 10.1007/BF00282443. [DOI] [PubMed] [Google Scholar]
  33. Panicker M. M., Minkley E. G., Jr DNA transfer occurs during a cell surface contact stage of F sex factor-mediated bacterial conjugation. J Bacteriol. 1985 May;162(2):584–590. doi: 10.1128/jb.162.2.584-590.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Panicker M. M., Minkley E. G., Jr Purification and properties of the F sex factor TraD protein, an inner membrane conjugal transfer protein. J Biol Chem. 1992 Jun 25;267(18):12761–12766. [PubMed] [Google Scholar]
  35. Peralta E. G., Hellmiss R., Ream W. Overdrive, a T-DNA transmission enhancer on the A. tumefaciens tumour-inducing plasmid. EMBO J. 1986 Jun;5(6):1137–1142. doi: 10.1002/j.1460-2075.1986.tb04338.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Peralta E. G., Ream L. W. T-DNA border sequences required for crown gall tumorigenesis. Proc Natl Acad Sci U S A. 1985 Aug;82(15):5112–5116. doi: 10.1073/pnas.82.15.5112. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Pohlman R. F., Genetti H. D., Winans S. C. Common ancestry between IncN conjugal transfer genes and macromolecular export systems of plant and animal pathogens. Mol Microbiol. 1994 Nov;14(4):655–668. doi: 10.1111/j.1365-2958.1994.tb01304.x. [DOI] [PubMed] [Google Scholar]
  38. Salch Y. P., Shaw P. D. Isolation and characterization of pathogenicity genes of Pseudomonas syringae pv. tabaci. J Bacteriol. 1988 Jun;170(6):2584–2591. doi: 10.1128/jb.170.6.2584-2591.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Schröder G., Waffenschmidt S., Weiler E. W., Schröder J. The T-region of Ti plasmids codes for an enzyme synthesizing indole-3-acetic acid. Eur J Biochem. 1984 Jan 16;138(2):387–391. doi: 10.1111/j.1432-1033.1984.tb07927.x. [DOI] [PubMed] [Google Scholar]
  40. Sen P., Pazour G. J., Anderson D., Das A. Cooperative binding of Agrobacterium tumefaciens VirE2 protein to single-stranded DNA. J Bacteriol. 1989 May;171(5):2573–2580. doi: 10.1128/jb.171.5.2573-2580.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Shaw C. H., Watson M. D., Carter G. H., Shaw C. H. The right hand copy of the nopaline Ti-plasmid 25 bp repeat is required for tumour formation. Nucleic Acids Res. 1984 Aug 10;12(15):6031–6041. doi: 10.1093/nar/12.15.6031. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Shirasu K., Kado C. I. Membrane location of the Ti plasmid VirB proteins involved in the biosynthesis of a pilin-like conjugative structure on Agrobacterium tumefaciens. FEMS Microbiol Lett. 1993 Aug 1;111(2-3):287–294. doi: 10.1111/j.1574-6968.1993.tb06400.x. [DOI] [PubMed] [Google Scholar]
  43. Shirasu K., Morel P., Kado C. I. Characterization of the virB operon of an Agrobacterium tumefaciens Ti plasmid: nucleotide sequence and protein analysis. Mol Microbiol. 1990 Jul;4(7):1153–1163. doi: 10.1111/j.1365-2958.1990.tb00690.x. [DOI] [PubMed] [Google Scholar]
  44. Shurvinton C. E., Hodges L., Ream W. A nuclear localization signal and the C-terminal omega sequence in the Agrobacterium tumefaciens VirD2 endonuclease are important for tumor formation. Proc Natl Acad Sci U S A. 1992 Dec 15;89(24):11837–11841. doi: 10.1073/pnas.89.24.11837. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Shurvinton C. E., Ream W. Stimulation of Agrobacterium tumefaciens T-DNA transfer by overdrive depends on a flanking sequence but not on helical position with respect to the border repeat. J Bacteriol. 1991 Sep;173(17):5558–5563. doi: 10.1128/jb.173.17.5558-5563.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Stachel S. E., Nester E. W. The genetic and transcriptional organization of the vir region of the A6 Ti plasmid of Agrobacterium tumefaciens. EMBO J. 1986 Jul;5(7):1445–1454. doi: 10.1002/j.1460-2075.1986.tb04381.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Stachel S. E., Timmerman B., Zambryski P. Activation of Agrobacterium tumefaciens vir gene expression generates multiple single-stranded T-strand molecules from the pTiA6 T-region: requirement for 5' virD gene products. EMBO J. 1987 Apr;6(4):857–863. doi: 10.1002/j.1460-2075.1987.tb04831.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. Stachel S. E., Zambryski P. C. Agrobacterium tumefaciens and the susceptible plant cell: a novel adaptation of extracellular recognition and DNA conjugation. Cell. 1986 Oct 24;47(2):155–157. doi: 10.1016/0092-8674(86)90437-x. [DOI] [PubMed] [Google Scholar]
  49. Thomashow L. S., Reeves S., Thomashow M. F. Crown gall oncogenesis: evidence that a T-DNA gene from the Agrobacterium Ti plasmid pTiA6 encodes an enzyme that catalyzes synthesis of indoleacetic acid. Proc Natl Acad Sci U S A. 1984 Aug;81(16):5071–5075. doi: 10.1073/pnas.81.16.5071. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Thompson D. V., Melchers L. S., Idler K. B., Schilperoort R. A., Hooykaas P. J. Analysis of the complete nucleotide sequence of the Agrobacterium tumefaciens virB operon. Nucleic Acids Res. 1988 May 25;16(10):4621–4636. doi: 10.1093/nar/16.10.4621. [DOI] [PMC free article] [PubMed] [Google Scholar]
  51. Thorstenson Y. R., Kuldau G. A., Zambryski P. C. Subcellular localization of seven VirB proteins of Agrobacterium tumefaciens: implications for the formation of a T-DNA transport structure. J Bacteriol. 1993 Aug;175(16):5233–5241. doi: 10.1128/jb.175.16.5233-5241.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  52. Tinland B., Koukolíková-Nicola Z., Hall M. N., Hohn B. The T-DNA-linked VirD2 protein contains two distinct functional nuclear localization signals. Proc Natl Acad Sci U S A. 1992 Aug 15;89(16):7442–7446. doi: 10.1073/pnas.89.16.7442. [DOI] [PMC free article] [PubMed] [Google Scholar]
  53. Van Larebeke N., Engler G., Holsters M., Van den Elsacker S., Zaenen I., Schilperoort R. A., Schell J. Large plasmid in Agrobacterium tumefaciens essential for crown gall-inducing ability. Nature. 1974 Nov 8;252(5479):169–170. doi: 10.1038/252169a0. [DOI] [PubMed] [Google Scholar]
  54. Veluthambi K., Ream W., Gelvin S. B. Virulence genes, borders, and overdrive generate single-stranded T-DNA molecules from the A6 Ti plasmid of Agrobacterium tumefaciens. J Bacteriol. 1988 Apr;170(4):1523–1532. doi: 10.1128/jb.170.4.1523-1532.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  55. Wang K., Herrera-Estrella L., Van Montagu M., Zambryski P. Right 25 bp terminus sequence of the nopaline T-DNA is essential for and determines direction of DNA transfer from agrobacterium to the plant genome. Cell. 1984 Sep;38(2):455–462. doi: 10.1016/0092-8674(84)90500-2. [DOI] [PubMed] [Google Scholar]
  56. Wang K., Stachel S. E., Timmerman B., VAN Montagu M., Zambryski P. C. Site-Specific Nick in the T-DNA Border Sequence as a Result of Agrobacterium vir Gene Expression. Science. 1987 Jan 30;235(4788):587–591. doi: 10.1126/science.235.4788.587. [DOI] [PubMed] [Google Scholar]
  57. Ward J. E., Akiyoshi D. E., Regier D., Datta A., Gordon M. P., Nester E. W. Characterization of the virB operon from an Agrobacterium tumefaciens Ti plasmid. J Biol Chem. 1988 Apr 25;263(12):5804–5814. [PubMed] [Google Scholar]
  58. Ward J. E., Jr, Dale E. M., Binns A. N. Activity of the Agrobacterium T-DNA transfer machinery is affected by virB gene products. Proc Natl Acad Sci U S A. 1991 Oct 15;88(20):9350–9354. doi: 10.1073/pnas.88.20.9350. [DOI] [PMC free article] [PubMed] [Google Scholar]
  59. Ward J. E., Jr, Dale E. M., Christie P. J., Nester E. W., Binns A. N. Complementation analysis of Agrobacterium tumefaciens Ti plasmid virB genes by use of a vir promoter expression vector: virB9, virB10, and virB11 are essential virulence genes. J Bacteriol. 1990 Sep;172(9):5187–5199. doi: 10.1128/jb.172.9.5187-5199.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  60. Ward J. E., Jr, Dale E. M., Nester E. W., Binns A. N. Identification of a virB10 protein aggregate in the inner membrane of Agrobacterium tumefaciens. J Bacteriol. 1990 Sep;172(9):5200–5210. doi: 10.1128/jb.172.9.5200-5210.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  61. Watson B., Currier T. C., Gordon M. P., Chilton M. D., Nester E. W. Plasmid required for virulence of Agrobacterium tumefaciens. J Bacteriol. 1975 Jul;123(1):255–264. doi: 10.1128/jb.123.1.255-264.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  62. Weiss A. A., Johnson F. D., Burns D. L. Molecular characterization of an operon required for pertussis toxin secretion. Proc Natl Acad Sci U S A. 1993 Apr 1;90(7):2970–2974. doi: 10.1073/pnas.90.7.2970. [DOI] [PMC free article] [PubMed] [Google Scholar]
  63. Winans S. C., Allenza P., Stachel S. E., McBride K. E., Nester E. W. Characterization of the virE operon of the Agrobacterium Ti plasmid pTiA6. Nucleic Acids Res. 1987 Jan 26;15(2):825–837. doi: 10.1093/nar/15.2.825. [DOI] [PMC free article] [PubMed] [Google Scholar]
  64. Winans S. C. Two-way chemical signaling in Agrobacterium-plant interactions. Microbiol Rev. 1992 Mar;56(1):12–31. doi: 10.1128/mr.56.1.12-31.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  65. Yanisch-Perron C., Vieira J., Messing J. Improved M13 phage cloning vectors and host strains: nucleotide sequences of the M13mp18 and pUC19 vectors. Gene. 1985;33(1):103–119. doi: 10.1016/0378-1119(85)90120-9. [DOI] [PubMed] [Google Scholar]
  66. Yanofsky M. F., Porter S. G., Young C., Albright L. M., Gordon M. P., Nester E. W. The virD operon of Agrobacterium tumefaciens encodes a site-specific endonuclease. Cell. 1986 Nov 7;47(3):471–477. doi: 10.1016/0092-8674(86)90604-5. [DOI] [PubMed] [Google Scholar]
  67. Young C., Nester E. W. Association of the virD2 protein with the 5' end of T strands in Agrobacterium tumefaciens. J Bacteriol. 1988 Aug;170(8):3367–3374. doi: 10.1128/jb.170.8.3367-3374.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  68. Yusibov V. M., Steck T. R., Gupta V., Gelvin S. B. Association of single-stranded transferred DNA from Agrobacterium tumefaciens with tobacco cells. Proc Natl Acad Sci U S A. 1994 Apr 12;91(8):2994–2998. doi: 10.1073/pnas.91.8.2994. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES