Identification of a novel promoter in the replication control region of plasmid R6K.
نویسندگان
چکیده
A novel source of transcription has been detected in the replication region of plasmid R6K by using fusions involving the galK reporter gene. The -35 and -10 consensus RNA polymerase binding sites were identified in the region overlapping the binding sites for the R6K-encoded replication protein pi. Transcription from this promoter, designated P2, is repressed in vivo by pi-protein levels that are inhibitory for replication. Promoter-down mutations in P2 induced in vitro by bisulfite mutagenesis result in a reduced copy number of a beta-replicon but not of a gamma-replicon. Implications of the role of P2 in R6K replication are discussed.
منابع مشابه
Altered (copy-up) forms of initiator protein pi suppress the point mutations inactivating the gamma origin of plasmid R6K.
The R6K gamma origin core contains the P2 promoter, whose -10 and -35 hexamers overlap two of the seven binding sites for the R6K-encoded pi protein. Two mutations, P2-201 and P2-203, which lie within the -35 region of P2, are shown to confer a promoter-down phenotype. We demonstrate here that these mutations prevent replication of a gamma origin core plasmid. To determine whether or not the re...
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عنوان ژورنال:
- Journal of bacteriology
دوره 174 14 شماره
صفحات -
تاریخ انتشار 1992