1
|
pBR322 vectors having tetracycline-dependent replication. Plasmid 2016; 84-85:20-6. [PMID: 26876942 DOI: 10.1016/j.plasmid.2016.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/04/2016] [Accepted: 02/10/2016] [Indexed: 12/16/2022]
Abstract
Few Escherichia coli cloning vectors are available that can both be stably maintained and efficiently cured. One such vector is pAM34, a pBR332 derivative constructed by Gil and Bouché (1991). Replication of this plasmid is driven by the lacZYA promoter under control of a gratuitous inducer. However, lac operator-repressor interactions are also used to regulate many expression systems which limit the utility of pAM34. In this report pAM34 has been modified by replacement of the lac regulatory elements with those of the transposon Tn10 tetracycline resistance module. This resulted in medium copy number plasmids that are dependent on the presence of tetracycline (or less satisfactorily, anhydrotetracycline) for replication. The tetracycline-dependent plasmids are rapidly lost in the absence of tetracycline and plasmid loss is markedly accelerated when the host strain expresses a tetracycline efflux pump.
Collapse
|
2
|
Cronan JE. A family of arabinose-inducible Escherichia coli expression vectors having pBR322 copy control. Plasmid 2006; 55:152-7. [PMID: 16139359 DOI: 10.1016/j.plasmid.2005.07.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2005] [Revised: 07/12/2005] [Accepted: 07/13/2005] [Indexed: 11/26/2022]
Abstract
The pBAD series of expression vectors have been widely used in Escherichia coli, Salmonella enterica, and related bacteria. However, a complication with pBAD24, the most popular of these plasmids, is that it does not contain the complete functional replication origin of pBR322 as was depicted in the original paper. Instead, pBAD24 has a pBR322-derived origin that lacks the rop gene that negatively regulates copy number and thus pBAD24 has an appreciably higher copy number than that of pBR322, particularly at elevated growth temperatures. A rop-containing derivative of pBAD24 (called pBAD322) having the copy number of pBR322 is reported together with derivatives of pBAD322 that encode resistance to chloramphenicol, kanamycin, tetracycline, spectinomycin/streptomycin, gentamycin, or trimethoprim in place of ampicillin.
Collapse
Affiliation(s)
- John E Cronan
- Department of Microbiology, University of Illinois, B103 Chemical and Life Sciences Laboratory, 601 S. Goodwin Ave., Urbana, IL 61801, USA.
| |
Collapse
|
3
|
Abstract
The idea that plasmids replicate within hosts at the expense of cell metabolic energy and preformed cellular blocks depicts plasmids as a kind of molecular parasites that, even when they may eventually provide plasmid-carrying strains with growth advantages over plasmid-free strains, doom hosts to bear an unavoidable metabolic burden. Due to the consistency with experimental data, this idea was rapidly adopted and used as a basis of different hypotheses to explain plasmid-host interactions. In this article we critically discuss current ideas about plasmid effects on host metabolism, and present evidence suggesting that the complex interaction between plasmids and hosts is related to the alteration of the cellular regulatory status.
Collapse
Affiliation(s)
- J C Diaz Ricci
- Instituto Superior de Investigaciones Biológicas (UNT-CONICET), Facultad de Bioquímica, Química y Farmacia, Tucuman, Argentina.
| | | |
Collapse
|
4
|
Zhang Y, Cronan JE. Transcriptional analysis of essential genes of the Escherichia coli fatty acid biosynthesis gene cluster by functional replacement with the analogous Salmonella typhimurium gene cluster. J Bacteriol 1998; 180:3295-303. [PMID: 9642179 PMCID: PMC107281 DOI: 10.1128/jb.180.13.3295-3303.1998] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/1998] [Accepted: 04/18/1998] [Indexed: 02/07/2023] Open
Abstract
The genes encoding several key fatty acid biosynthetic enzymes (called the fab cluster) are clustered in the order plsX-fabH-fabD-fabG-acpP-fabF at min 24 of the Escherichia coli chromosome. A difficulty in analysis of the fab cluster by the polar allele duplication approach (Y. Zhang and J. E. Cronan, Jr., J. Bacteriol. 178:3614-3620, 1996) is that several of these genes are essential for the growth of E. coli. We overcame this complication by use of the fab gene cluster of Salmonella typhimurium, a close relative of E. coli, to provide functions necessary for growth. The S. typhimurium fab cluster was isolated by complementation of an E. coli fabD mutant and was found to encode proteins with > 94% homology to those of E. coli. However, the S. typhimurium sequences cannot recombine with the E. coli sequences required to direct polar allele duplication via homologous recombination. Using this approach, we found that although approximately 60% of the plsX transcripts initiate at promoters located far upstream and include the upstream rpmF ribosomal protein gene, a promoter located upstream of the plsX coding sequence (probably within the upstream gene, rpmF) is sufficient for normal growth. We have also found that the fabG gene is obligatorily cotranscribed with upstream genes. Insertion of a transcription terminator cassette (omega-Cm cassette) between the fabD and fabG genes of the E. coli chromosome abolished fabG transcription and blocked cell growth, thus providing the first indication that fabG is an essential gene. Insertion of the omega-Cm cassette between fabH and fabD caused greatly decreased transcription of the fabD and fabG genes and slower cellular growth, indicating that fabD has only a weak promoter(s).
Collapse
Affiliation(s)
- Y Zhang
- Department of Microbiology, University of Illinois, Urbana 61801, USA
| | | |
Collapse
|
5
|
Frost LS, Ippen-Ihler K, Skurray RA. Analysis of the sequence and gene products of the transfer region of the F sex factor. Microbiol Rev 1994; 58:162-210. [PMID: 7915817 PMCID: PMC372961 DOI: 10.1128/mr.58.2.162-210.1994] [Citation(s) in RCA: 274] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bacterial conjugation results in the transfer of DNA of either plasmid or chromosomal origin between microorganisms. Transfer begins at a defined point in the DNA sequence, usually called the origin of transfer (oriT). The capacity of conjugative DNA transfer is a property of self-transmissible plasmids and conjugative transposons, which will mobilize other plasmids and DNA sequences that include a compatible oriT locus. This review will concentrate on the genes required for bacterial conjugation that are encoded within the transfer region (or regions) of conjugative plasmids. One of the best-defined conjugation systems is that of the F plasmid, which has been the paradigm for conjugation systems since it was discovered nearly 50 years ago. The F transfer region (over 33 kb) contains about 40 genes, arranged contiguously. These are involved in the synthesis of pili, extracellular filaments which establish contact between donor and recipient cells; mating-pair stabilization; prevention of mating between similar donor cells in a process termed surface exclusions; DNA nicking and transfer during conjugation; and the regulation of expression of these functions. This review is a compendium of the products and other features found in the F transfer region as well as a discussion of their role in conjugation. While the genetics of F transfer have been described extensively, the mechanism of conjugation has proved elusive, in large part because of the low levels of expression of the pilus and the numerous envelope components essential for F plasmid transfer. The advent of molecular genetic techniques has, however, resulted in considerable recent progress. This summary of the known properties of the F transfer region is provided in the hope that it will form a useful basis for future comparison with other conjugation systems.
Collapse
Affiliation(s)
- L S Frost
- Department of Microbiology, University of Alberta, Edmonton, Canada
| | | | | |
Collapse
|
6
|
Siemering KR, Praszkier J, Pittard AJ. Interaction between the antisense and target RNAs involved in the regulation of IncB plasmid replication. J Bacteriol 1993; 175:2895-906. [PMID: 7684039 PMCID: PMC204607 DOI: 10.1128/jb.175.10.2895-2906.1993] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Physical analysis of RNA I, the small antisense RNA which regulates the replication of IncB miniplasmid pMU720, showed that it is a highly structured molecule containing an imperfectly paired stem closed by a 6-base hairpin loop. Mutational studies revealed that a 3-base sequence in the hairpin loop is critical to the interaction between RNA I and its complementary target in the RepA mRNA (RNA II). Furthermore, a 2-base interior loop in the upper stem was found to play an important role in facilitating effective binding between RNA I and RNA II. From these analyses, a model describing the molecular mechanism of binding between RNA I and RNA II is proposed.
Collapse
Affiliation(s)
- K R Siemering
- Department of Microbiology, University of Melbourne, Parkville, Victoria, Australia
| | | | | |
Collapse
|
7
|
Womble DD, Rownd RH. Genetic and physical map of plasmid NR1: comparison with other IncFII antibiotic resistance plasmids. Microbiol Rev 1988; 52:433-51. [PMID: 3070319 PMCID: PMC373158 DOI: 10.1128/mr.52.4.433-451.1988] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
8
|
Gerdes K. The parB (hok/sok) Locus of Plasmid R1: A General Purpose Plasmid Stabilization System. Nat Biotechnol 1988. [DOI: 10.1038/nbt1288-1402] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
9
|
Golub EI, Panzer HA. The F factor of Escherichia coli carries a locus of stable plasmid inheritance stm, similar to the parB locus of plasmid RI. MOLECULAR & GENERAL GENETICS : MGG 1988; 214:353-7. [PMID: 3070354 DOI: 10.1007/bf00337735] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We found that a 1.4 kb fragment of the F factor of Escherichia coli (coordinates 62.8-64.2) considerably increased the stable inheritance of different plasmids which carried it. The fragment has a 589 bp DNA sequence (coordinates 63.3-63.9) with extensive homology to the parB locus of plasmid RI and, probably like the parB region, ensures the presence of plasmids in bacterial populations by killing those cells which have lost the plasmid.
Collapse
Affiliation(s)
- E I Golub
- Radiobiology Laboratories, Yale University School of Medicine, New Haven, CT 06510
| | | |
Collapse
|
10
|
Lenski RE, Bouma JE. Effects of segregation and selection on instability of plasmid pACYC184 in Escherichia coli B. J Bacteriol 1987; 169:5314-6. [PMID: 3312174 PMCID: PMC213944 DOI: 10.1128/jb.169.11.5314-5316.1987] [Citation(s) in RCA: 72] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We use a mathematical model to analyze the dynamics of loss of nonconjugative pACYC184 from populations of Escherichia coli B in glucose-limited continuous culture. This model incorporates both plasmid segregation and selection against plasmid carriage. It is concluded that there is intense selection against plasmid carriage (s = 0.3 per culture generation), which amplifies the frequency of segregants arising de novo.
Collapse
Affiliation(s)
- R E Lenski
- Department of Ecology and Evolutionary Biology, University of California, Irvine 92717
| | | |
Collapse
|
11
|
Perez-Casal JF, Crosa JH. Novel incompatibility and partition loci for the REPI replication region of plasmid ColV-K30. J Bacteriol 1987; 169:5078-86. [PMID: 2822663 PMCID: PMC213911 DOI: 10.1128/jb.169.11.5078-5086.1987] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The minimum pColV-K30 REPI region necessary for replication was located within a ca. 1.3-kilobase DNA segment. Adjacent to the essential replication sequences, there are two DNA regions that express incompatibility with plasmids containing the F secondary replicon of the F EcoRI fragment f7. One of these regions corresponds to incE, already described in that F plasmid fragment which expresses incompatibility with f7-containing plasmids. The other is a novel sequence that we designated incF, which confers incompatibility with REPI, P307, and f7 derivatives, cis-acting pColV-K30 sequences conferring stability to REPI-containing plasmids were also identified and localized noncontiguous to REPI, ca. 20 kilobases downstream from the aerobactin iron transport genes, which were thus flanked by REPI and its partition (par) sequences.
Collapse
Affiliation(s)
- J F Perez-Casal
- Department of Microbiology and Immunology, School of Medicine, Oregon Health Sciences University, Portland 97201
| | | |
Collapse
|
12
|
Loh S, Ray A, Cram D, O'Gorman L, Skurray R. Location of a second partitioning region (ParL) on the F plasmid. FEMS Microbiol Lett 1986. [DOI: 10.1111/j.1574-6968.1986.tb01789.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
13
|
Vernet T, McDonald IJ, Cameron DR, Visentin LP. Stable maintenance in chemostat-grown Escherichia coli of pBR322 and pACYC184 by disruption of the tetracycline resistance gene. Biosci Rep 1985; 5:29-37. [PMID: 3886036 DOI: 10.1007/bf01117438] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Plasmid stability was studied in antibiotic-free chemostat cultures. Disruption, either by deletion or insertion, of the tetracycline resistance gene in the EcoR1/EcoRV region of the cloning vector pBR322 or in the HindIII/BamH1 region of pACYC184 yields plasmids markedly more stable than the parent plasmids. Thus, at least for these two instances, cloning of a partitioning (par) locus is not prerequisite for plasmid maintenance.
Collapse
|
14
|
Jackson R, Cram D, Ray A, DiBerardino D, Skurray R. Cloning and analysis of pif, replication and leading regions of the F plasmid. MOLECULAR & GENERAL GENETICS : MGG 1984; 197:129-36. [PMID: 6096669 DOI: 10.1007/bf00327933] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We describe the molecular cloning of BglII fragments of the hybrid plasmid pRS5 (pSC101 and EcoRI fragments of F; f7, f5, f3 and f6). The clones isolated were examined for the expression of F-specified replication, incompatibility, mobilization and inhibition of T7 bacteriophage multiplication. Proteins directed by the BglII clones were labelled in Escherichia coli K12 maxicells and analyzed by SDS-polyacrylamide gel electrophoresis. The sizes of previously reported proteins, encoded by the replication, incompatibility and leading regions encompassed by these plasmids have been confirmed in this study. In addition, the results demonstrate that a pif gene, which encodes an 80,000 dalton polypeptide essential for the inhibition T7 phage multiplication, is located on the BglII fragment that spans the junction of EcoRI fragments f7 and f5.
Collapse
|
15
|
Cram D, Ray A, O'Gorman L, Skurray R. Transcriptional analysis of the leading region in F plasmid DNA transfer. Plasmid 1984; 11:221-33. [PMID: 6205412 DOI: 10.1016/0147-619x(84)90028-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Transcriptional activity associated with the leading region (53.8-66.7F) in F DNA transfer has been shown by RNA-DNA hybridization studies to occur on the anterior segment extending from 59.4 to 66.7F. Promoter-probe analysis of cloned leading region segments detected two promoters within the transcribed portion of the leading region. The promoter active across the 64.7F EcoRI site on the transferred F strand was associated with the expression of two polypeptides, 6d and 13.5p, located between 64.7-66.6F. However, no definite role could be ascribed to the second promoter operative through the 66.6F Bg/II site located in close proximity to oriT, the origin of transfer.
Collapse
|