J. Bacteriol., Mar 1996, 1491-1497, Vol 178, No. 6
Copyright © 1996, American Society for Microbiology

Nucleotide sequence and characterization of the trbABC region of the IncI1 Plasmid R64: existence of the pnd gene for plasmid maintenance within the transfer region

N Furuya and T Komano
Department of Biology, Tokyo Metropolitan University, Minamiohsawa, Hachioji, Japan.

A 6.72-kb DNA sequence between the exc gene and the oriT operon within the transfer region of IncI1 plasmid R64 was sequenced and characterized. Three novel transfer genes, trbA, trbB, and trbC, were found in this region, along with the pnd gene responsible for plasmid maintenance. The trbABC genes appear to be organized into an operon located adjacent to the oriT operon in the opposite orientation. The trbA and trbC genes were shown to be indispensable for R64 plasmid transfer, while residual transfer activity was detected in the case of R64 derivatives carrying the trbB++ deletion mutation. The T7 RNA polymerase-promoter system revealed that the trbB gene produced a 43- kDa protein and the trbC gene produced an 85-kDa protein. The nucleotide sequence of the pnd gene is nearly identical to that of plasmid R483, indicating a function in plasmid maintenance. The plasmid stability test indicated that the mini-R64 derivatives with the pnd gene are more stably maintained in Escherichia coli cells under nonselective conditions than the mini-R64 derivatives without the pnd gene. It was also shown that the R64 transfer system itself is involved in plasmid stability to a certain degree. Deletion of the pnd gene from the tra+ mini-R64 derivative did not affect transfer frequency. DNA segments between the exc and trbA genes for IncI1 plasmids R64, Colb- P9, and R144 were compared in terms of their physical and genetic organization.

This article has been cited by other articles:

• Elton, T. C., Holland, S. J., Frost, L. S., Hazes, B. (2005). F-Like Type IV Secretion Systems Encode Proteins with Thioredoxin Folds That Are Putative DsbC Homologues. J. Bacteriol. 187: 8267-8277 [Abstract] [Full Text]  
• Li, W.-C., Huang, F.-Y., Liu, C.-P., Weng, L.-C., Wang, N.-Y., Chiu, N.-C., Chiang, C.-S. (2005). Ceftriaxone Resistance of Nontyphoidal Salmonella enterica Isolates in Northern Taiwan Attributable to Production of CTX-M-14 and CMY-2 {beta}-Lactamases. J. Clin. Microbiol. 43: 3237-3243 [Abstract] [Full Text]  
• Buscher, B. A., Conover, G. M., Miller, J. L., Vogel, S. A., Meyers, S. N., Isberg, R. R., Vogel, J. P. (2005). The DotL Protein, a Member of the TraG-Coupling Protein Family, Is Essential for Viability of Legionella pneumophila Strain Lp02. J. Bacteriol. 187: 2927-2938 [Abstract] [Full Text]  
• Park, W., Jeon, C. O., Hohnstock-Ashe, A. M., Winans, S. C., Zylstra, G. J., Madsen, E. L. (2003). Identification and Characterization of the Conjugal Transfer Region of the pCg1 plasmid from Naphthalene-Degrading Pseudomonas putida Cg1. Appl. Environ. Microbiol. 69: 3263-3271 [Abstract] [Full Text]  
• Franco, A. A., Cheng, R. K., Chung, G.-T., Wu, S., Oh, H.-B., Sears, C. L. (1999). Molecular Evolution of the Pathogenicity Island of Enterotoxigenic Bacteroides fragilis Strains. J. Bacteriol. 181: 6623-6633 [Abstract] [Full Text]  
• Romine, M. F., Stillwell, L. C., Wong, K.-K., Thurston, S. J., Sisk, E. C., Sensen, C., Gaasterland, T., Fredrickson, J. K., Saffer, J. D. (1999). Complete Sequence of a 184-Kilobase Catabolic Plasmid from Sphingomonas aromaticivorans F199. J. Bacteriol. 181: 1585-1602 [Abstract] [Full Text]  
• Horiuchi, T., Komano, T. (1998). Mutational Analysis of Plasmid R64 Thin Pilus Prepilin: the Entire Prepilin Sequence Is Required for Processing by Type IV Prepilin Peptidase. J. Bacteriol. 180: 4613-4620 [Abstract] [Full Text]  
• Segal, G., Purcell, M., Shuman, H. A. (1998). Host cell killing and bacterial conjugation require overlapping sets of genes within a 22-kb region of the Legionella pneumophila genome. Proc. Natl. Acad. Sci. USA 95: 1669-1674 [Abstract] [Full Text]  
• Vogel, J. P., Andrews, H. L., Wong, S. K., Isberg, R. R. (1998). Conjugative Transfer by the Virulence System of Legionella pneumophila. Science 279: 873-876 [Abstract] [Full Text]  
• Sakai, D., Horiuchi, T., Komano, T. (2001). ATPase Activity and Multimer Formation of PilQ Protein Are Required for Thin Pilus Biogenesis in Plasmid R64. J. Biol. Chem. 276: 17968-17975 [Abstract] [Full Text]