Sex pheromone plasmid pAD1-encoded aggregation substance of Enterococcus faecalis is positively regulated in trans by traE1.
Sex-pheromone-plasmid-bearing strains of Enterococcus faecalis react with sex pheromone to induce the expression of an adhesin, the so-called aggregation substance, on their cell surface. Here we show that, by complementation studies, for sex-pheromone plasmid pAD1, expression of the structural gene asa1, coding for an aggregation substance, is mediated by a diffusible factor encoded on pAD1. We were able to demonstrate that a small open reading frame, traE1, is sufficient for transcription of the operon containing asa1. A model for expression of asa1 under the influence of the positive regulator is presented, which is supported by our observation that regulation involves an all-or-nothing induction phenomenon, leading to cells either fully expressing asa1 or not at all.
Muscholl
A
A
Lehrstuhl für Mikrobiologie, Universität München, Germany.
Galli
D
D
Wanner
G
G
Wirth
R
R
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D015152:Blotting, Northern; D013293:Enterococcus faecalis / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005809:Genes, Regulator; D010957:Plasmids; D012724:Sex Attractants / Q000096:biosynthesis / Q000235:genetics*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D012724:Sex Attractants; C065937:aggregation substance, Enterococcus faecalis