Virulence factors and antibiotic resistance determinants are distributed among Gram-negative bacteria by conjugative plasmids. All such plasmids express pili, filamentous structures which are essential for establishing the contact between donor and recipient cells necessary for DNA transfer. In the F conjugative system, more than fourteen genes in the F transfer operon appear to be involved in the synthesis and expression of F-pili. Many of these products have not been identified, and their molecular role is not yet understood. Recently we have shown that synthesis of F-pilus subunits requires the processing of F-traA product to F-pilin. The processing reaction requires an activity from a previously unidentified transfer operon gene (traQ), and may require additional unidentified activities as well. We plan to identify the genes and gene products involved in F-pilin subunit synthesis, and investigate the nature of the biochemical reactions which occur in this pathway. We also plan, with transducing phages and chimeric plasmid derivitives, to identify all of the genes and gene products which are involved in the assembly of F-pilin subunits, and to investigate their interactions with each other and with F-pilin during the assembly process. The studies proposed are expected to contribute to our understanding of pilus synthesis and expression, and to elucidate the role of pilus assembly and retraction in conjugation.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI014426-11
Application #
3125745
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1978-09-01
Project End
1988-08-31
Budget Start
1987-09-01
Budget End
1988-08-31
Support Year
11
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Texas A&M University
Department
Type
Schools of Medicine
DUNS #
City
College Station
State
TX
Country
United States
Zip Code
77845
Maneewannakul, K; Kathir, P; Endley, S et al. (1996) Construction of derivatives of the F plasmid pOX-tra715: characterization of traY and traD mutants that can be complemented in trans. Mol Microbiol 22:197-205
Maneewannakul, K; Maneewannakul, S; Ippen-Ihler, K (1995) Characterization of traX, the F plasmid locus required for acetylation of F-pilin subunits. J Bacteriol 177:2957-64
Maneewannakul, S; Maneewannakul, K; Ippen-Ihler, K (1994) The pKSM710 vector cassette provides tightly regulated lac and T7lac promoters and strategies for manipulating N-terminal protein sequences. Plasmid 31:300-7
Moore, D; Hamilton, C M; Maneewannakul, K et al. (1993) The Escherichia coli K-12 F plasmid gene traX is required for acetylation of F pilin. J Bacteriol 175:1375-83
Maneewannakul, K; Maneewannakul, S; Ippen-Ihler, K (1993) Synthesis of F pilin. J Bacteriol 175:1384-91
Maneewannakul, K; Ippen-Ihler, K (1993) Construction and analysis of F plasmid traR, trbJ, and trbH mutants. J Bacteriol 175:1528-31
Maneewannakul, S; Maneewannakul, K; Ippen-Ihler, K (1992) Characterization, localization, and sequence of F transfer region products: the pilus assembly gene product TraW and a new product, TrbI. J Bacteriol 174:5567-74
Maneewannakul, S; Kathir, P; Ippen-Ihler, K (1992) Characterization of the F plasmid mating aggregation gene traN and of a new F transfer region locus trbE. J Mol Biol 225:299-311
Maneewannakul, K; Maneewannakul, S; Ippen-Ihler, K (1992) Sequence alterations affecting F plasmid transfer gene expression: a conjugation system dependent on transcription by the RNA polymerase of phage T7. Mol Microbiol 6:2961-73
Maneewannakul, S; Maneewannakul, K; Ippen-Ihler, K (1991) Characterization of trbC, a new F plasmid tra operon gene that is essential to conjugative transfer. J Bacteriol 173:3872-8

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