title: Regulation and expression of the bacteriophage mu mom gene: mapping of the transactivation (dad) function to the C region.
abstract: Expression of the bacteriophage Mu mom gene is under tight regulatory control. One of the factors required for mom gene expression is the trans-acting function (designated Dad) provided by another Mu gene. To facilitate studies on the signals mediating mom regulation, we have constructed a mom-lacZ fusion plasmid which synthesizes beta-galactosidase only when the Mu Dad transactivating function is provided. lambda pMu phages carrying different segments of the Mu genome have been assayed for their ability to transactivate beta-galactosidase expression by the fusion plasmid. The results of these analyses indicated that the Dad transactivation function is encoded between the leftmost EcoRI site and the lys gene of Mu; this region includes the C gene, which is required for expression of all Mu late genes. Cloning of an approx. 800-bp fragment containing the C gene produced a plasmid which could complement MuC- phages for growth and could transactivate the mom-lacZ fusion plasmid to produce beta-galactosidase. These results suggest that the C gene product mediates the Dad transactivation function.
mesh_terms: D010582:Bacteriophage lambda / Q000235:genetics; D010583:Bacteriophage mu / Q000235:genetics*; D002874:Chromosome Mapping; D005786:Gene Expression Regulation; D005809:Genes, Regulator; D005814:Genes, Viral; D010957:Plasmids; D001616:beta-Galactosidase / Q000235:genetics
chemical_list: D001616:beta-Galactosidase