Abstract
A 74-kDa iron-regulated outer membrane protein of Vibrio cholerae acts as the receptor for the V. cholerae iron-siderophore complex, ferric vibriobactin. MBG14, a mutant of V. cholerae 0395 containing a TnphoA insertion in a gene designated viuA, lacks this 74-kDa outer membrane protein and is unable to bind or utilize exogenous ferric vibriobactin. Introduction of a plasmid containing the complete viuA coding sequence and 513 bp of upstream DNA into MBG14 restored ferric vibriobactin utilization to the mutant. The DNA insert in this plasmid was sequenced, revealing a single open reading frame of 2,061 bp, encoding a deduced protein of 687 amino acids with a predicted molecular mass of 76,417 Da and a predicted initial signal sequence of 37 amino acids. ViuA showed only weak homology to two iron-regulated outer membrane proteins in Escherichia coli, IutA and FecA. Construction of viuA::TnphoA gene fusions allowed study of the regulation of viuA expression by iron. This regulation in E. coli was dependent on the fur gene. Northern (RNA) blot analysis of RNA from wild-type V. cholerae grown in high- and low-iron media revealed a monocistronic viuA message that was negatively regulated by iron at the transcriptional level. Primer extension analysis identified a single transcriptional start site, located 243 bp above the translational start site. The promoter region of viuA contained two interrupted dyad symmetric nucleotide sequences, overlapping the -10 and -35 boxes, each similar to the E. coli Fur binding consensus sequence. Another iron-regulated gene in V. cholerae that is negatively regulated by fur, irgA, requires a positive transcriptional activator (irgB) for expression. However, a strain of V. cholerae mutant in irgB was unaffected in viuA expression. These studies suggest that there is conserved, global coordinate iron regulation in V. cholerae by fur; additional regulatory factors, superimposed upon the fur system, may provide more precise control of individual iron-regulated genes.
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Selected References
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- Actis L. A., Tolmasky M. E., Farrell D. H., Crosa J. H. Genetic and molecular characterization of essential components of the Vibrio anguillarum plasmid-mediated iron-transport system. J Biol Chem. 1988 Feb 25;263(6):2853–2860. [PubMed] [Google Scholar]
- Bagg A., Neilands J. B. Mapping of a mutation affecting regulation of iron uptake systems in Escherichia coli K-12. J Bacteriol. 1985 Jan;161(1):450–453. doi: 10.1128/jb.161.1.450-453.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bell P. E., Nau C. D., Brown J. T., Konisky J., Kadner R. J. Genetic suppression demonstrates interaction of TonB protein with outer membrane transport proteins in Escherichia coli. J Bacteriol. 1990 Jul;172(7):3826–3829. doi: 10.1128/jb.172.7.3826-3829.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brickman T. J., Ozenberger B. A., McIntosh M. A. Regulation of divergent transcription from the iron-responsive fepB-entC promoter-operator regions in Escherichia coli. J Mol Biol. 1990 Apr 20;212(4):669–682. doi: 10.1016/0022-2836(90)90229-F. [DOI] [PubMed] [Google Scholar]
- Bullen J. J. The significance of iron in infection. Rev Infect Dis. 1981 Nov-Dec;3(6):1127–1138. doi: 10.1093/clinids/3.6.1127. [DOI] [PubMed] [Google Scholar]
- Calderwood S. B., Mekalanos J. J. Confirmation of the Fur operator site by insertion of a synthetic oligonucleotide into an operon fusion plasmid. J Bacteriol. 1988 Feb;170(2):1015–1017. doi: 10.1128/jb.170.2.1015-1017.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Calderwood S. B., Mekalanos J. J. Iron regulation of Shiga-like toxin expression in Escherichia coli is mediated by the fur locus. J Bacteriol. 1987 Oct;169(10):4759–4764. doi: 10.1128/jb.169.10.4759-4764.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Crosa J. H. Genetics and molecular biology of siderophore-mediated iron transport in bacteria. Microbiol Rev. 1989 Dec;53(4):517–530. doi: 10.1128/mr.53.4.517-530.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Crosa J. H. The relationship of plasmid-mediated iron transport and bacterial virulence. Annu Rev Microbiol. 1984;38:69–89. doi: 10.1146/annurev.mi.38.100184.000441. [DOI] [PubMed] [Google Scholar]
- De Grandis S., Ginsberg J., Toone M., Climie S., Friesen J., Brunton J. Nucleotide sequence and promoter mapping of the Escherichia coli Shiga-like toxin operon of bacteriophage H-19B. J Bacteriol. 1987 Sep;169(9):4313–4319. doi: 10.1128/jb.169.9.4313-4319.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Farrell D. H., Mikesell P., Actis L. A., Crosa J. H. A regulatory gene, angR, of the iron uptake system of Vibrio anguillarum: similarity with phage P22 cro and regulation by iron. Gene. 1990 Jan 31;86(1):45–51. doi: 10.1016/0378-1119(90)90112-5. [DOI] [PubMed] [Google Scholar]
- Goldberg M. B., Boyko S. A., Calderwood S. B. Positive transcriptional regulation of an iron-regulated virulence gene in Vibrio cholerae. Proc Natl Acad Sci U S A. 1991 Feb 15;88(4):1125–1129. doi: 10.1073/pnas.88.4.1125. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldberg M. B., Boyko S. A., Calderwood S. B. Transcriptional regulation by iron of a Vibrio cholerae virulence gene and homology of the gene to the Escherichia coli fur system. J Bacteriol. 1990 Dec;172(12):6863–6870. doi: 10.1128/jb.172.12.6863-6870.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldberg M. B., DiRita V. J., Calderwood S. B. Identification of an iron-regulated virulence determinant in Vibrio cholerae, using TnphoA mutagenesis. Infect Immun. 1990 Jan;58(1):55–60. doi: 10.1128/iai.58.1.55-60.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Griffiths G. L., Sigel S. P., Payne S. M., Neilands J. B. Vibriobactin, a siderophore from Vibrio cholerae. J Biol Chem. 1984 Jan 10;259(1):383–385. [PubMed] [Google Scholar]
- Hantke K. Cloning of the repressor protein gene of iron-regulated systems in Escherichia coli K12. Mol Gen Genet. 1984;197(2):337–341. doi: 10.1007/BF00330982. [DOI] [PubMed] [Google Scholar]
- Hantke K. Regulation of ferric iron transport in Escherichia coli K12: isolation of a constitutive mutant. Mol Gen Genet. 1981;182(2):288–292. doi: 10.1007/BF00269672. [DOI] [PubMed] [Google Scholar]
- Hawley D. K., McClure W. R. Compilation and analysis of Escherichia coli promoter DNA sequences. Nucleic Acids Res. 1983 Apr 25;11(8):2237–2255. doi: 10.1093/nar/11.8.2237. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kyte J., Doolittle R. F. A simple method for displaying the hydropathic character of a protein. J Mol Biol. 1982 May 5;157(1):105–132. doi: 10.1016/0022-2836(82)90515-0. [DOI] [PubMed] [Google Scholar]
- Litwin C. M., Boyko S. A., Calderwood S. B. Cloning, sequencing, and transcriptional regulation of the Vibrio cholerae fur gene. J Bacteriol. 1992 Mar;174(6):1897–1903. doi: 10.1128/jb.174.6.1897-1903.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Manoil C., Beckwith J. TnphoA: a transposon probe for protein export signals. Proc Natl Acad Sci U S A. 1985 Dec;82(23):8129–8133. doi: 10.1073/pnas.82.23.8129. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mekalanos J. J., Swartz D. J., Pearson G. D., Harford N., Groyne F., de Wilde M. Cholera toxin genes: nucleotide sequence, deletion analysis and vaccine development. Nature. 1983 Dec 8;306(5943):551–557. doi: 10.1038/306551a0. [DOI] [PubMed] [Google Scholar]
- Michaelis S., Inouye H., Oliver D., Beckwith J. Mutations that alter the signal sequence of alkaline phosphatase in Escherichia coli. J Bacteriol. 1983 Apr;154(1):366–374. doi: 10.1128/jb.154.1.366-374.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miller S. I., Landfear S. M., Wirth D. F. Cloning and characterization of a Leishmania gene encoding a RNA spliced leader sequence. Nucleic Acids Res. 1986 Sep 25;14(18):7341–7360. doi: 10.1093/nar/14.18.7341. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miller V. L., Mekalanos J. J. A novel suicide vector and its use in construction of insertion mutations: osmoregulation of outer membrane proteins and virulence determinants in Vibrio cholerae requires toxR. J Bacteriol. 1988 Jun;170(6):2575–2583. doi: 10.1128/jb.170.6.2575-2583.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Neilands J. B. Microbial envelope proteins related to iron. Annu Rev Microbiol. 1982;36:285–309. doi: 10.1146/annurev.mi.36.100182.001441. [DOI] [PubMed] [Google Scholar]
- Neilands J. B. Microbial iron compounds. Annu Rev Biochem. 1981;50:715–731. doi: 10.1146/annurev.bi.50.070181.003435. [DOI] [PubMed] [Google Scholar]
- O'Brien I. G., Cox G. B., Gibson F. Enterochelin hydrolysis and iron metabolism in Escherichia coli. Biochim Biophys Acta. 1971 Jun 22;237(3):537–549. doi: 10.1016/0304-4165(71)90274-1. [DOI] [PubMed] [Google Scholar]
- Pearson W. R., Lipman D. J. Improved tools for biological sequence comparison. Proc Natl Acad Sci U S A. 1988 Apr;85(8):2444–2448. doi: 10.1073/pnas.85.8.2444. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pettis G. S., Brickman T. J., McIntosh M. A. Transcriptional mapping and nucleotide sequence of the Escherichia coli fepA-fes enterobactin region. Identification of a unique iron-regulated bidirectional promoter. J Biol Chem. 1988 Dec 15;263(35):18857–18863. [PubMed] [Google Scholar]
- Pollack J. R., Ames B. N., Neilands J. B. Iron transport in Salmonella typhimurium: mutants blocked in the biosynthesis of enterobactin. J Bacteriol. 1970 Nov;104(2):635–639. doi: 10.1128/jb.104.2.635-639.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SIMON E. H., TESSMAN I. THYMIDINE-REQUIRING MUTANTS OF PHAGE T4. Proc Natl Acad Sci U S A. 1963 Sep;50:526–532. doi: 10.1073/pnas.50.3.526. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Salinas P. C., Tolmasky M. E., Crosa J. H. Regulation of the iron uptake system in Vibrio anguillarum: evidence for a cooperative effect between two transcriptional activators. Proc Natl Acad Sci U S A. 1989 May;86(10):3529–3533. doi: 10.1073/pnas.86.10.3529. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sciortino C. V., Finkelstein R. A. Vibrio cholerae expresses iron-regulated outer membrane proteins in vivo. Infect Immun. 1983 Dec;42(3):990–996. doi: 10.1128/iai.42.3.990-996.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sigel S. P., Payne S. M. Effect of iron limitation on growth, siderophore production, and expression of outer membrane proteins of Vibrio cholerae. J Bacteriol. 1982 Apr;150(1):148–155. doi: 10.1128/jb.150.1.148-155.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sigel S. P., Stoebner J. A., Payne S. M. Iron-vibriobactin transport system is not required for virulence of Vibrio cholerae. Infect Immun. 1985 Feb;47(2):360–362. doi: 10.1128/iai.47.2.360-362.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stoebner J. A., Butterton J. R., Calderwood S. B., Payne S. M. Identification of the vibriobactin receptor of Vibrio cholerae. J Bacteriol. 1992 May;174(10):3270–3274. doi: 10.1128/jb.174.10.3270-3274.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stoebner J. A., Payne S. M. Iron-regulated hemolysin production and utilization of heme and hemoglobin by Vibrio cholerae. Infect Immun. 1988 Nov;56(11):2891–2895. doi: 10.1128/iai.56.11.2891-2895.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Struyvé M., Moons M., Tommassen J. Carboxy-terminal phenylalanine is essential for the correct assembly of a bacterial outer membrane protein. J Mol Biol. 1991 Mar 5;218(1):141–148. doi: 10.1016/0022-2836(91)90880-f. [DOI] [PubMed] [Google Scholar]
- Tautz D., Renz M. An optimized freeze-squeeze method for the recovery of DNA fragments from agarose gels. Anal Biochem. 1983 Jul 1;132(1):14–19. doi: 10.1016/0003-2697(83)90419-0. [DOI] [PubMed] [Google Scholar]
- de Lorenzo V., Wee S., Herrero M., Neilands J. B. Operator sequences of the aerobactin operon of plasmid ColV-K30 binding the ferric uptake regulation (fur) repressor. J Bacteriol. 1987 Jun;169(6):2624–2630. doi: 10.1128/jb.169.6.2624-2630.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- von Heijne G. How signal sequences maintain cleavage specificity. J Mol Biol. 1984 Feb 25;173(2):243–251. doi: 10.1016/0022-2836(84)90192-x. [DOI] [PubMed] [Google Scholar]
- von Heijne G. Signal sequences. The limits of variation. J Mol Biol. 1985 Jul 5;184(1):99–105. doi: 10.1016/0022-2836(85)90046-4. [DOI] [PubMed] [Google Scholar]