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TraI, a LuxI homologue, is responsible for production of conjugation factor, the Ti plasmid N-acylhomoserine lactone autoinducer
- Source :
- Proceedings of the National Academy of Sciences. 91:4639-4643
- Publication Year :
- 1994
- Publisher :
- Proceedings of the National Academy of Sciences, 1994.
-
Abstract
- Conjugal transfer of the nopaline-type Agrobacterium Ti plasmid pTiC58 is regulated by a transcriptional activator, TraR, and a diffusible signal molecule, conjugation factor (CF). CF is a member of a family of substituted homoserine lactones (HSLs) that act as coinducers for regulating gene expression in diverse Gram-negative bacteria by a mechanism called autoinduction. In Vibrio fischeri HSL production is conferred by the luxI gene. Homologues of this gene are responsible for HSL production by other Gram-negative bacteria. A gene that we call traI, conferring production of material with CF activity, was localized to a 1-kb region at the upstream end of tra3 of pTiC58. Spectroscopy showed that the activity was authentic CF. Sequence analysis showed that traI could encode a protein of 211 amino acids, TraI, that is related to the proteins responsible for HSL production by other bacteria. A second, partial open reading frame immediately downstream of traI could encode a protein related to TrbB of plasmid RP4, which is required for conjugal transfer. Transcription of traI and of the downstream tra3 genes requires TraR and CF and initiates from the traI promoter. The results show that traI is responsible for CF production, that it is the first gene of the tra3 operon, and that expression of this operon is regulated by autoinduction.
- Subjects :
- DNA, Bacterial
Transcription, Genetic
Operon
Agrobacterium
Molecular Sequence Data
Homoserine
Biology
Lactones
Open Reading Frames
chemistry.chemical_compound
Ti plasmid
Plasmid
Amino Acid Sequence
Cloning, Molecular
Promoter Regions, Genetic
Gene
Genetics
Multidisciplinary
Base Sequence
Escherichia coli Proteins
DNA Helicases
Gene Expression Regulation, Bacterial
biology.organism_classification
Open reading frame
chemistry
Biochemistry
Conjugation, Genetic
Multigene Family
Autoinducer
Research Article
Plasmids
Rhizobium
Subjects
Details
- ISSN :
- 10916490 and 00278424
- Volume :
- 91
- Database :
- OpenAIRE
- Journal :
- Proceedings of the National Academy of Sciences
- Accession number :
- edsair.doi.dedup.....619c30d9d712c2286213929597316560