Control of cole 1 plasmid replication: Enhancement of binding of RNA I to the primer transcript by the rom protein

Tomizawa, Jun-ichi; Som, Tapan

doi:10.1016/0092-8674(84)90282-4

Cited by 215 publications

(111 citation statements)

References 9 publications

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“…Note that for ColE1 plasmids in E. coli cells, there are 20 -40 copies per cell, and this copy number is stringently regulated (34,35). Moreover, stalling of the replication fork at the terETus complex only occurs in ϳ80% of the cases.…”

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confidence: 99%

Direct Evidence for the Formation of Precatenanes during DNA Replication

Cebrián

Castán

López‐Martínez

et al. 2015

Journal of Biological Chemistry

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Background: Changes in DNA topology during replication are still poorly understood. Results: Classical genetics and two-dimensional agarose gel electrophoresis showed that RIs tensioned in the absence of Topo IV. Conclusion:The results indicated that replication forks swivel in vivo leading to the formation of precatenanes as replication progresses. Significance: This conclusion ends a long lasting debate on the formation of precatenanes during replication.

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confidence: 99%

Direct Evidence for the Formation of Precatenanes during DNA Replication

Cebrián

Castán

López‐Martínez

et al. 2015

Journal of Biological Chemistry

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“…For example, replication of plasmid ColE1 is controlled by pairing between RNA II, the precursor of the primer for DNA replication, and RNA I, a small regulatory RNA that is complementary to the 5' end of RNA II. This interaction, which is facilitated by a protein called Rop or Rom, interferes with the processing of RNA II to form the mature primer RNA Itoh 1981~ Lacatena et al 1984;Tomizawa and Som 1984}. The expression of genes encoding proreins can also be controlled by the specific interaction of mRNAs and complementary (antisense} RNAs.…”

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confidence: 99%

Control of gene expression in bacteriophage P22 by a small antisense RNA. II. Characterization of mutants defective in repression.

Liao²,

McClure³

et al. 1987

Genes Dev.

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In recent years, it has become clear that some biological regulatory mechanisms are mediated by interactions between complementary RNA molecules Ireviewed by Green et al. 1986}. For example, replication of plasmid ColE1 is controlled by pairing between RNA II, the precursor of the primer for DNA replication, and RNA I, a small regulatory RNA that is complementary to the 5' end of RNA II. This interaction, which is facilitated by a protein called Rop or Rom, interferes with the processing of RNA II to form the mature primer RNA Itoh 1981~ Lacatena et al. 1984;Tomizawa and Som 1984}. The expression of genes encoding proreins can also be controlled by the specific interaction of mRNAs and complementary (antisense} RNAs. Naturally occurring regulation by antisense RNAs has been described for several bacterial proteins, including TnlO transposase (Simons and Kleckner 1983}, the replication proteins of plasmids R1 {Light and Molin 1983} and pT181 {Kumar and Novick 1985}, and the OmpF outer membrane protein of Escherichia coli (Mizuno et al. 1984}.In this paper, we present evidence that the synthesis of phage P22 antirepressor is regulated by a small antisense RNA called sar {for small antisense regulatory RNA). P22 antirepressor is a protein that inhibits the specific DNA-binding activity of P22 c2 repressor, phage k cI repressor, and the analogous repressors of other, related phages (for review, see Susskind and Youderian 19831. These repressors, which are structurally and functionally similar but differ in DNA sequence specificity, turn off transcription of lyric phage genes during lysogeny. The antirepressor gene, ant, is expressed from a strong, rightward promoter called Pant, which is regulated by two repressor proteins [see

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“…However, copy number control is typically mediated by specific plasmid-encoded regulatory systems, many of which act at the initiation step. For example, in ColEl-like plasmids, initiation is controlled by a small inhibitory RNA (RNAI) that hybridizes to primer RNA and by a small peptide (Rop or Rom) that stabilizes hybrid formation (27).Only a few host mutations have been found to affect plasmid copy number, and those that do often act by decreasing plasmid stability rather than altering the control of initiation or replication rate (2). However, mutations at the E. coli pcnB locus were recently shown to reduce the copy numbers of ColEl-like plasmids (17), suggesting that PcnB could be a novel replication function.…”

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Genetics and sequence analysis of the pcnB locus, an Escherichia coli gene involved in plasmid copy number control

1989

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Mutations at the Escherichia coli pcnB locus reduce the copy number of ColEl-like plasmids. We isolated additional mutations in this gene and conducted a preliminary characterization of its product. F-prime elements carrying the pcnB region were constructed and used to show that the mutations were recessive. The wild-type pcnB gene was cloned into a low-copy-number plasmid, and its nucleotide sequence was determined. The sequence analysis indicated that pcnB is probably the first gene in an operon that contains one or more additional genes of unknown function. The pcnB locus should encode a polypeptide of 47,349 daltons (Da). A protein of this size was observed in minicells carrying apcnB+ plasmid, and transposon insertions and deletions that truncated this protein generally abolished pcnB function. One exceptional transposon insertion at the promoter-distal end of the pcnB gene truncated the 47-kDa protein by about 20% but did not abolish complementation activity, indicating that the C-terminus of the PcnB product is dispensable. The deduced amino acid sequence of PcnB revealed numerous charged residues and, with 10% arginines, an overall basic character, suggesting that PcnB might interact with DNA or RNA in a structural capacity. Disruption of the pcnB gene by insertional mutagenesis caused a reduction in growth rate, indicating that PcnB has an important cellular function.Studies of DNA synthesis in Escherichia coli have identified numerous functions required for chromosomal replication, including DNA polymerase III, which contains at least eight subunits, DNA gyrase, DNA primase, RNA polymerase, DNA helicases, and Hu, the major histonelike protein in the cell (19). Many of these replication proteins, especially those needed for DNA unwinding and primer processing, are also involved in plasmid replication, although unrelated plasmids may utilize different combinations of host functions. For example, the F element requires DNA polymerase III, whereas ColEl-like plasmids such as pBR322 employ the host DNA polymerase I (25). However, copy number control is typically mediated by specific plasmid-encoded regulatory systems, many of which act at the initiation step. For example, in ColEl-like plasmids, initiation is controlled by a small inhibitory RNA (RNAI) that hybridizes to primer RNA and by a small peptide (Rop or Rom) that stabilizes hybrid formation (27).Only a few host mutations have been found to affect plasmid copy number, and those that do often act by decreasing plasmid stability rather than altering the control of initiation or replication rate (2). However, mutations at the E. coli pcnB locus were recently shown to reduce the copy numbers of ColEl-like plasmids (17), suggesting that PcnB could be a novel replication function. In this report we describe the isolation of additional pcnB alleles, the cloning and sequence analysis of this gene, and the identification and nature of its protein product. Disruption of the pcnB gene by transposon insertion was not lethal to the cell but did result in impaire...

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Control of cole 1 plasmid replication: Enhancement of binding of RNA I to the primer transcript by the rom protein

Cited by 215 publications

References 9 publications

Direct Evidence for the Formation of Precatenanes during DNA Replication

Direct Evidence for the Formation of Precatenanes during DNA Replication

Control of gene expression in bacteriophage P22 by a small antisense RNA. II. Characterization of mutants defective in repression.

Genetics and sequence analysis of the pcnB locus, an Escherichia coli gene involved in plasmid copy number control

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