Summary
The transcriptional units in the basic replicon of plasmid R1 were defined by means of gene fusions. It was found that in the wild-type plasmid there is one large mRNA encoding both the control factor copB and the positive replication factor repA. A second, internal transcription initiation site, the repA promoter, is usually repressed by the copB protein, and is therefore only of significance in the absence of this control factor. By induction of the repA promoter through gradual dilution of the copB repressor it was shown that translation of repA-mRNA, controlled by the copA-RNA, is significantly increased only when the rate of repA transcription is above a certain level. No indication was found for a possible interference from convergent copA transcription on repA transcription.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
An G, Friesen JD (1979) Plasmid vehicles for direct cloning of Escherichia coli promoters. J Bacteriol 140:400–407
Bertani G (1951) Studies of lysogenesis I. The mode of phage liberation by lysogenic Escherichia coli. J Bacteriol 62:293–300
Bolivar F, Rodriguez RL, Betlach MC, Boyer HW (1977) Construction and characterization of new cloning vehicles. II. A multipurpose cloning system. Gene 2:95–113
Cohen SN, Chang ACY, Hsu L (1972) Nonchromosomal antibiotic resistance in bacteria: genetic transformation of Escherichia coli by R-factor DNA. Proc Natl Acad Sci USA 69:2110–2114
Humphreys GO, Willshaw GA, Smith HR, Anderson ES (1976). Mutagenesis of plasmid DNA with hydroxylamine: Isolation of mutants of multicopy plasmids. Mol Gen Genet 145:101–108
Larsen JEL, Gerdes K, Light J, Molin S (1984) Low-copy-number plasmid-cloning vectors amplifiable by derepression of an inserted foreign promoter. Gene, in press
Light J, Molin S (1981) Replication control functions of plasmid R1 act as inhibitors of expression of a gene required for replication. Mol Gen Genet 184:56–61
Light J, Molin S (1982a) The sites of action of the two copy number control functions of plasmid R1. Mol Gen Genet 187:486–493
Light J, Molin S (1982b) Expression of a copy number control gene (copB) of plasmid R1 is constitutive and growth rate dependent. J Bacteriol 151:1129–1135
Light J, Molin S (1983) Post-transcriptional control of expression of the repA gene of plasmid R1 mediated by a small RNA molecule. EMBO J 2:93–98
Meacock PA, Cohen SN (1980) Partitioning of bacterial plasmids during cell division: a cis-acting locus that accomplishes stable plasmid inheritance. Cell 20:529–542
Miller JH (1972) Experiments in molecular genetics. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York
Molin S, Stougaard P, Uhlin BE, Gustafsson P, Nordström K (1979) Clustering of genes involved in replication, incompatibility, and stable maintenance of the resistance plasmid R1drd-19. J Bacteriol 138:70–79
Molin S, Stougaard P, Light J, Nordström M, Nordström K (1981) Isolation and characterization of new copy mutants of plasmid R1, and identification of a polypeptide involved in copy number control. Mol Gen Genet 181:123–130
Nielsen PF, Molin S (1984) How the R1 replication control system responds to copy number derivations. Plasmid, in press
Riise E, Stougaard P, Bindslev B, Nordström K, Molin S (1982) Molecular cloning and functional characterization of the copy number control gene, copB, from plasmid R1. J Bacteriol 151:1136–1145
Rosen J, Ryder T, Ohtsubo E, Ohtsubo H (1981) Role of DNA transcripts in replication incompatibility and copy number control in antibiotic resistance plasmid derivatives. Nature 290:794–797
Stougaard P, Molin S (1981) Vertical dye-buoyant density gradients for rapid analysis and preparation of plasmid DNA. Anal Biochem 118:191–193
Stougaard P, Molin S, Nordström K, Hansen FG (1981a) The nucleotide sequence of the replication control region of the resistance plasmid R1drd-19. Mol Gen Genet 181:116–122
Stougaard P, Molin S, Nordström K (1981b) RNA molecules involved in copy number control and incompatibility of plasmid R1. Proc Natl Acad Sci USA 78:6008–6012
Stougaard P, Light J, Molin S (1982) Convergent transcription interferes with expression of the copy number control gene, copA, from plasmid R1. EMBO J 1:323–328
Szybalski EH, Szybalski W (1979) A comprehensive molecular map of bacteriophage lambda. Gene 7:217–270
Uhlin BE, Nordström K (1975) Plasmid incompatibility and control of replication copy mutants of the R-factor R1 in Escherichia coli K12. J Bacteriol 124:641–649
Author information
Authors and Affiliations
Additional information
Communicated by J. Schell
Rights and permissions
About this article
Cite this article
Light, J., Riise, E. & Molin, S. Transcription and its regulation in the basic replicon region of plasmid R1. Mol Gen Genet 198, 503–508 (1985). https://doi.org/10.1007/BF00332947
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00332947