Summary
Site-specific deletions and insertions in the replication region of plasmid R1 have generated a new class of copy mutants that are present in the cell with 10–15-fold increased copy number. All mutations described inactivate a copy number control gene which is distinct from another cop inc gene that was identified previously (Molin and Nordström 1980). Insertion of the lac operon lacking the normal lac promoter has been used to determine the direction of transcription of this cop gene. The mutants may all be complemented by wild-type plasmid derivatives and are thus recessive. In incompatibility tests with wild-type R1 plasmids, these mutants are indistinguishable from the wild-type plasmid. It therefore seems that this cop function does not play an important role for the incompatibility function. A polypeptide, molecular weight 11,000, has been identified as being the product of this cop gene.
Similar content being viewed by others
References
Appleyard RK (1954) Segregation of new lysogenic types during growth of a doubly lysogenic strain derived from Escherichia coli K-12. Genetics 39:440–452
Beard JP, Connolly JC (1975) Detection of a protein, similar to the sex pilus subunit, in the outer membrane of Escherichia coli cells carrying a derepressed F-like R-factor. J Bacteriol 122:59–65
Bergfors S, Burman LG, Eklöf PH, Nordström K, Tärnvik A (1972) Transferable and non-transferable drug resistance in enteric bacteria isolated from urinary specimens in Northern Sweden. Acta Pathol Microbiol Scand [B] 80:511–518
Bertani G (1951) Studies on lysogenesis. I The mode of phage liberation by lysogenic Escherichia coli. J Bacteriol 62:293–300
Blohm D, Goebel W (1978) Restriction map of the antibiotic resistance plasmid R1drd-19 and its derivatives pKN102 (R1drd-19B2) and R1drd-16 for the enzymes BamHI, HindIII, EcoRI and SalI. Mol Gen Genet 16:119–127
Cabello F, Timmis K, Cohen SN (1976) Replication control in a composite plasmid constructed by in vitro linkage of two distinct replicons. Nature 259:285–290
Chou J, Lemaux PG, Casadaban MJ, Cohen SN (1979) Transposition protein of Tn3: identification and characterization of an essential repressor-controlled gene product. Nature 282:801–806
Clark JD, Maaløe O (1967) DNA replication and the division cycle in Escherichia coli. J Mol Biol 23:99–112
Clewell DB, Helinski DR (1969) Supercoiled circular DNA-protein complex in E. coli: purification and induced conversion to an open circular DNA form. Proc Natl Acad Sci USA 62:1159–1166
Dougan G, Sherratt D (1977) The transposon Tn1 as a probe for studying ColE1 structure and function. Mol Gen Genet 151:151–160
Dürwald H, Hoffmann-Berling H (1968) Endonuclease I-deficient and ribonuclease I-deficient Escherichia coli mutants. J Mol Biol 34:331–346
Frazer AC, Curtiss III R (1975) Production properties and utility of bacterial minicells. Curr Top Microbiol Immunol 69:1–84
Goebel W, Bonewald R (1975) Class of small multicopy plasmids originating from the mutant antibiotic resistance factor Rdrd-19B2. J Bacteriol 123:658–665
Gustafsson P, Nordström K (1978) Temperature-dependent and amber copy mutants of plasmid R1drd-19 in Escherichia coli. Plasmid 1:134–144
Humphreys GO, Willshaw GA, Anderson EA (1975) A simple method for the preparation of large quantities of pure plasmid DNA. Biochim Biophys Acta 383:457–463
Kennedy N, Beutin L, Achtman M, Skurray R, Rahmsdorf U, Herrlich P (1977) Conjugation proteins encoded by the F sex factor. Nature (London) 270:580–585
Koltek R, Oertel W, Goebel W (1978) Isolation and characterization of the minimal fragment required for autonomous replication of a copy mutant (pKN102) of the antibiotic resistance factor R1. Mol Gen Genet 162:51–58
Kolter R, Helinski DR (1979) Regulation of initiation of DNA replication. Ann Rev Genet 13:355–392
Laemmli UK (1970) Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227:680–685
Matsubara K, Takeda Y (1976) Role of the tof gene in the production and perpetuation of the λdv plasmid. Mol Gen Genet 142:226–230
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 R1. J Bacteriol 138:70–79
Molin S, Nordström K (1980) Control of plasmid R` replication: Functions involved in replication, copy number control, incompatibility and switch-off of replication. J Bacteriol 141:111–120
Molin S, Diaz R, Uhlin BE, Nordström K (1980) Runaway replication of plasmid R1 is not caused by loss of replication inhibitor activity of the cop gene. J Bacteriol 143:1046–1048
Nordström K, Ingram LC, Lundbäck A (1972) Mutations in R factors of Escherichia coli causing an increased number of R-factor copies per chromosome. J Bacteriol 110:562–569
Nordström K, Molin S, Aagaard-Hansen H (1980) Partitioning of plasmid R1 in Escherichia coli. I. Kinetics of loss of plasmid derivatives deleted of the par region. Plasmid 4:215–227
Nordström K, Molin S, Aagaard-Hansen H (1981) Partitioning of plasmid R1 in Escherichia coli. II. Incompatibility properties of the partitioning system. Plasmid 5: in press
Novick RP, Clowes RC, Cohen SN, Curtiss III R, Datta N, Falkow S (1976) Uniform nomenclature for bacterial plasmids: A proposal. Bacteriol Rev 40:168–189
Oertel W, Kollek R, Beck E, Goebel W (1979) The nucleotide sequence of a DNA fragment from the replication origin of the antibiotic resistance factor R1drd-19. Mol Gen Genet 171:277–285
Pritchard RH, Barth PT, Collins J (1969) Control of DNA synthesis in bacteria. Symp Soc Gen Microbiol 19:263–297
Shepard HM, Gelfand GH, Polisky B (1979) Analysis of a recessive plasmid copy number mutant: Evidence for negative control of ColE1 replication. Cell 18:267–275
Stougaard P, Molin S, Nordström K, Hansen FG (1981) The nucleotide sequence of the replication control region of the resistance plasmid R1drd-19. Mol Gen Genet 181:116–122
Uhlin BE, Nordström K (1975) Plasmid incompatibility and control of replication: Copy mutants of the R-factor R1 in Escherichia coli K-12. J Bacteriol 124:641–649
Uhlin BE, Nordström K (1978) A runaway-replication mutant of plasmid R1drd-19: Temperature-dependent loss of copy number control. Mol Gen Genet 165:167–179
Zubay G (1973) In vitro synthesis of protein in microbial systems. Annu Rev Gen 7:267–287
Author information
Authors and Affiliations
Additional information
Communicated by D. Sherratt
Rights and permissions
About this article
Cite this article
Molin, S., Stougaard, P., Light, J. et al. 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 (1981). https://doi.org/10.1007/BF00339015
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00339015