TraI, a LuxI homologue, is responsible for production of conjugation factor, the Ti plasmid N-acylhomoserine lactone autoinducer.

• DOI: 10.1073/pnas.91.11.4639
• Publication Date: 2006-05-31T12:47:09Z
• Authors: I Hwang; P L Li; L Zhang; K R Piper; D M Cook; M E Tate; S K Farrand
• Keywords: Autoinducer; Transcription; Homoserine

Conjugal transfer of the nopaline-type Agrobacterium Ti plasmid pTiC58 is regulated by a transcriptional activator, TraR, and diffusible signal molecule, conjugation factor (CF). CF member family substituted homoserine lactones (HSLs) that act as coinducers for regulating gene expression in diverse Gram-negative bacteria mechanism called autoinduction. In Vibrio fischeri HSL production conferred luxI gene. Homologues this are responsible other bacteria. A we call traI, conferring material with activity, was localized to 1-kb region at upstream end tra3 pTiC58. Spectroscopy showed activity authentic CF. Sequence analysis traI could encode protein 211 amino acids, TraI, related proteins second, partial open reading frame immediately downstream TrbB RP4, which required conjugal transfer. Transcription genes requires TraR initiates from promoter. The results show production, it first operon, operon