Abstract
The traW gene of the Escherichia coli K-12 sex factor, F, encodes one of the numerous proteins required for conjugative transfer of this plasmid. We have found that the nucleotide sequence of traW encodes a 210-amino-acid, 23,610-Da polypeptide with a characteristic amino-terminal signal peptide sequence; in DNA from the F lac traW546 amber mutant, the traW open reading frame is interrupted at codon 141. Studies of traW expression in maxicells in the presence and absence of ethanol demonstrate that the traW product does undergo signal sequence processing. Cell fractionation experiments additionally demonstrated that mature TraW is a periplasmic protein. Electron microscopy also showed that F lac traW546 hosts do not express F pili, confirming that TraW is required for F-pilus assembly. Our nucleotide sequence also revealed the existence of an additional gene, trbI, located between traC and traW. The trbI gene encodes a 128-amino-acid polypeptide which could be identified as a 14-kDa protein product. Fractionation experiments demonstrated that TrbI is an intrinsic inner-membrane protein. Hosts carrying the pOX38-trbI::kan insertion mutant plasmids that we constructed remained quite transfer proficient but exhibited increased resistance to F-pilus-specific phages. Mutant plasmids pOX38-trbI472 and pOX38-trbI473 expressed very long F pili, suggestive of a pilus retraction deficiency. Expression of an excess of TrbI in hosts carrying a wild-type pOX38 plasmid also caused F-pilus-specific phage resistance. The possibility that TrbI influences the kinetics of pilus outgrowth and/or retraction is discussed.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Achtman M., Skurray R. A., Thompson R., Helmuth R., Hall S., Beutin L., Clark A. J. Assignment of tra cistrons to EcoRI fragments of F sex factor DNA. J Bacteriol. 1978 Mar;133(3):1383–1392. doi: 10.1128/jb.133.3.1383-1392.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burke J. M., Novotny C. P., Fives-Taylor P. Defective F pili and other characteristics of Flac and Hfr Escherichia coli mutants resistant to bacteriophage R17. J Bacteriol. 1979 Nov;140(2):525–531. doi: 10.1128/jb.140.2.525-531.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chandler M., Galas D. J. Cointegrate formation mediated by Tn9. II. Activity of IS1 is modulated by external DNA sequences. J Mol Biol. 1983 Oct 15;170(1):61–91. doi: 10.1016/s0022-2836(83)80227-7. [DOI] [PubMed] [Google Scholar]
- Chang A. C., Cohen S. N. Construction and characterization of amplifiable multicopy DNA cloning vehicles derived from the P15A cryptic miniplasmid. J Bacteriol. 1978 Jun;134(3):1141–1156. doi: 10.1128/jb.134.3.1141-1156.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gottesman M. E., Adhya S., Das A. Transcription antitermination by bacteriophage lambda N gene product. J Mol Biol. 1980 Jun 15;140(1):57–75. doi: 10.1016/0022-2836(80)90356-3. [DOI] [PubMed] [Google Scholar]
- Guyer M. S., Reed R. R., Steitz J. A., Low K. B. Identification of a sex-factor-affinity site in E. coli as gamma delta. Cold Spring Harb Symp Quant Biol. 1981;45(Pt 1):135–140. doi: 10.1101/sqb.1981.045.01.022. [DOI] [PubMed] [Google Scholar]
- Ham L. M., Firth N., Skurray R. Nucleotide sequence of the F plasmid transfer gene, traH: identification of a new gene and a promoter within the transfer operon. Gene. 1989 Jan 30;75(1):157–165. doi: 10.1016/0378-1119(89)90392-2. [DOI] [PubMed] [Google Scholar]
- Ippen-Ihler K. A., Minkley E. G., Jr The conjugation system of F, the fertility factor of Escherichia coli. Annu Rev Genet. 1986;20:593–624. doi: 10.1146/annurev.ge.20.120186.003113. [DOI] [PubMed] [Google Scholar]
- Ito K., Sato T., Yura T. Synthesis and assembly of the membrane proteins in E. coli. Cell. 1977 Jul;11(3):551–559. doi: 10.1016/0092-8674(77)90073-3. [DOI] [PubMed] [Google Scholar]
- Kathir P., Ippen-Ihler K. Construction and characterization of derivatives carrying insertion mutations in F plasmid transfer region genes, trbA, artA, traQ, and trbB. Plasmid. 1991 Jul;26(1):40–54. doi: 10.1016/0147-619x(91)90035-u. [DOI] [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]
- Maneewannakul S., Kathir P., Ippen-Ihler K. Characterization of the F plasmid mating aggregation gene traN and of a new F transfer region locus trbE. J Mol Biol. 1992 May 20;225(2):299–311. doi: 10.1016/0022-2836(92)90923-8. [DOI] [PubMed] [Google Scholar]
- Maneewannakul S., Kathir P., Moore D., Le L. A., Wu J. H., Ippen-Ihler K. Location of F plasmid transfer operon genes traC and traW and identification of the traW product. J Bacteriol. 1987 Nov;169(11):5119–5124. doi: 10.1128/jb.169.11.5119-5124.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Maneewannakul S., Maneewannakul K., Ippen-Ihler K. Characterization of trbC, a new F plasmid tra operon gene that is essential to conjugative transfer. J Bacteriol. 1991 Jun;173(12):3872–3878. doi: 10.1128/jb.173.12.3872-3878.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mead D. A., Kemper B. Chimeric single-stranded DNA phage-plasmid cloning vectors. Biotechnology. 1988;10:85–102. doi: 10.1016/b978-0-409-90042-2.50010-6. [DOI] [PubMed] [Google Scholar]
- Miki T., Horiuchi T., Willetts N. S. Identification and characterization of four new tra cistrons on the E. coli K12 sex factor F. Plasmid. 1978 Jun;1(3):316–323. doi: 10.1016/0147-619x(78)90048-3. [DOI] [PubMed] [Google Scholar]
- Moore D., Maneewannakul K., Maneewannakul S., Wu J. H., Ippen-Ihler K., Bradley D. E. Characterization of the F-plasmid conjugative transfer gene traU. J Bacteriol. 1990 Aug;172(8):4263–4270. doi: 10.1128/jb.172.8.4263-4270.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moore D., Sowa B. A., Ippen-Ihler K. A new activity in the Ftra operon which is required for F-pilin synthesis. Mol Gen Genet. 1982;188(3):459–464. doi: 10.1007/BF00330049. [DOI] [PubMed] [Google Scholar]
- Moore D., Wu J. H., Kathir P., Hamilton C. M., Ippen-Ihler K. Analysis of transfer genes and gene products within the traB-traC region of the Escherichia coli fertility factor, F. J Bacteriol. 1987 Sep;169(9):3994–4002. doi: 10.1128/jb.169.9.3994-4002.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Remaut E., Stanssens P., Fiers W. Plasmid vectors for high-efficiency expression controlled by the PL promoter of coliphage lambda. Gene. 1981 Oct;15(1):81–93. doi: 10.1016/0378-1119(81)90106-2. [DOI] [PubMed] [Google Scholar]
- Schandel K. A., Maneewannakul S., Ippen-Ihler K., Webster R. E. A traC mutant that retains sensitivity to f1 bacteriophage but lacks F pili. J Bacteriol. 1987 Jul;169(7):3151–3159. doi: 10.1128/jb.169.7.3151-3159.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schandel K. A., Maneewannakul S., Vonder Haar R. A., Ippen-Ihler K., Webster R. E. Nucleotide sequence of the F plasmid gene, traC, and identification of its product. Gene. 1990 Nov 30;96(1):137–140. doi: 10.1016/0378-1119(90)90354-t. [DOI] [PubMed] [Google Scholar]
- Schandel K. A., Muller M. M., Webster R. E. Localization of TraC, a protein involved in assembly of the F conjugative pilus. J Bacteriol. 1992 Jun;174(11):3800–3806. doi: 10.1128/jb.174.11.3800-3806.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wu J. H., Ippen-Ihler K. Nucleotide sequence of traQ and adjacent loci in the Escherichia coli K-12 F-plasmid transfer operon. J Bacteriol. 1989 Jan;171(1):213–221. doi: 10.1128/jb.171.1.213-221.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wu J. H., Kathir P., Ippen-Ihler K. The product of the F plasmid transfer operon gene, traF, is a periplasmic protein. J Bacteriol. 1988 Aug;170(8):3633–3639. doi: 10.1128/jb.170.8.3633-3639.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wu J. H., Moore D., Lee T., Ippen-Ihler K. Analysis of Escherichia coli K12 F factor transfer genes: traQ, trbA, and trbB. Plasmid. 1987 Jul;18(1):54–69. doi: 10.1016/0147-619x(87)90078-3. [DOI] [PubMed] [Google Scholar]