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2 edition of UV mutagenesis of lac Z mutants of Escherichia coli K-12. found in the catalog.

UV mutagenesis of lac Z mutants of Escherichia coli K-12.

Zeena Hussein Al-Hasani

UV mutagenesis of lac Z mutants of Escherichia coli K-12.

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Published by University of East Anglia in Norwich .
Written in English


Edition Notes

Thesis (M.Phil.) - University of East Anglia, School of Biological Sciences, 1978.

ID Numbers
Open LibraryOL13845777M

uvrB5uvrD3recB21 strains ofEscherichia coli K Nonsense (trpE65) rever-sionwasalso comparedin similar derivatives ofE. coli B/ruvrAI TheuvrD mutation reduced mutagenesis in every case, but had its main effect in cells ultraviolet irradiated with low fluences . Nucleotide excision repair (NER) is a multistep process that leads to the formation of gaps in the DNA duplex that must be filled by repair synthesis and covalently sealed by DNA ligase. This chapter discusses the NER in prokaryotes. In the bacterium Escherichia coli, both specific recognition of base damage and incision of the affected DNA strand on either side of sites of base damage are.   For example, the SOS response is required for phage λ untargeted mutagenesis (I chikawa-R yo and K ondo ), stress-induced point mutagenesis in E. coli in the Lac assay (M c K enzie et al. ), ciprofloxacin (antibiotic)-resistance mutagenesis induced by exposure to ciprofloxacin (C irz et al. ), mutagenesis in aging colonies in a.


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UV mutagenesis of lac Z mutants of Escherichia coli K-12. by Zeena Hussein Al-Hasani Download PDF EPUB FB2

UV mutagenesis in Escherichia coli K Cell survival and mutation frequency of the chromosomal genes lacZ, rpoB, ompF, and ampA KEVIN LIN ANDALICE WANG Department of Microbiology and Immunology, UBC UV-induced mutation frequency and cell survivability was examined in Escherichia coliK- 12 Size: KB.

Abstract. Previous genetic studies have indicated that most UV mutagenesis in Escherichia coli requires the participation of the umuD and umuC gene products.

However the mechanism of UV mutagenesis is not yet understood and the roles of the UmuD and Author: John R.

Battista, Takehiko Nohmi, Caroline E. Donnelly, Graham C. Walker. LeClerc JE, Istock NL. Specificity of UV mutagenesis in the lac promoter of M13lac hybrid phage DNA.

Nature. Jun 17; ()– Schaaper RM, Dunn RL. Spectra of spontaneous mutations in Escherichia coli strains defective in mismatch correction: the nature of in vivo DNA replication by: Summary Selection for defective reversion induction, after UV treatment of E.

coli K 12, yielded uvm mutants. These mutants exhibited highly reduced or no UV mutability for all loci tested although they were moderately and normally mutable by X-rays and EMS, by: and Escherichia coli K obtained from mutants of Escherichia coli. Bacteriol (9): UV mutagenesis in E.

coli and λ bacteriophage may be due primarily to the Author: Alireza Goodarzi. Spontaneous and UV-InducedMutations in Escherichia coli K Strains with Altered or AbsentDNAPolymerase I MUTATION IN E. COLI K Poll MUTANTS TABLE 1.

Strains ofbacteria strains, therefore, UV mutagenesis in /polA bacteria is umuCdependent. The lab utilizes UV mutagenesis with wild-type Escherichia coli and a UV-sensitive isogenic derivative optimized for undergraduate use.

The labs take advantage of the simplicity of E. coli in a realistic genetic investigation using safe UV irradiation methods for. Steinborn G () Uvm mutants of Escherichia coli K12 deficient in UV mutagenesis.

Isolation of uvm mutants and their phenotypical characterization in DNA repair and mutagenesis. Mol Gen Genet –93 PubMed CrossRef Google Scholar. This experiment examines the effects of UV on the survival of cells in log and stationary phase. Escherichia coli SMR, which is genetically identical to E.

coli FC40 but was constructed independently, was used in order to examine this phenomenon. coli SMR has a slightly leaky Lac-phenotype which is not sufficient to allow the. Wang, T.V. and K.C. Smith () Role of the umuC gene in postreplication repair in UV-irradiated Escherichia coli K uvrB. Mutation Res.

Wang, T.V. and K.C. Smith (a) Postreplicational formation and repair of DNA double-strand breaks in UV-irradiated Escherichia coli uvrB cells. Mutation Res. Three mechanisms for ultraviolet radiation mutagenesis in Escherichia coli K uvrB5: specificity for the production of back and suppressor mutants.

Mutat Res. Dec; (2)– Sargentini NJ, Smith KC. Much of spontaneous mutagenesis in Escherichia coli is due to error-prone DNA repair: implications for spontaneous carcinogenesis. Induced mutagenesis is widely used for selection of microorganisms producing biologically active substances and further improving of their activities.

However, it is rarely used toward lactic acid bacteria (LAB) due to their genetic specificity. Determination of LABs sensitivity to UV light and evaluate the effectiveness of UV-induced mutagenesis by positive selection of antibiotic resistant.

Uvm mutants of Escherichia coli K12 selected for defective UV reversion induction have previously been reported to differ considerably from the UV-reversion-less recA and lexA mutants with regard to survival or mutagenic response to UV, X-rays and alkylating agents.

In the present study, the phenotypic characterization of uvm mutants was extended to investigate several cellular processes which. Mutagenesis in the lacI gene target of E. coli: improved analysis for lacI(d) and lacO mutants.

Swerdlow SJ(1), Schaaper RM(2). Author information: (1)Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, NCUnited States; Biology Department, Thiel College, 75 College Avenue. The induction of mutations by ultraviolet light and delayed photoreversal in bacteria defective for SOS mutagenesis is discussed in terms of two models: the two-step misincorporation and bypass model, and the model involving simple deamination of cytosine-containing dimers.

In phage S13 the latter appears to be the predominant mechanism. In Escherichia coli there is little evidence that the. Kato T, Shinoura Y. Isolation and characterization of mutants of Escherichia coli deficient in induction of mutations by ultraviolet light. Mol Gen Genet.

Nov 14; (2)– Elledge SJ, Walker GC. Proteins required for ultraviolet light and chemical mutagenesis. Identification of the products of the umuC locus of Escherichia coli. Escherichia coli (strain K12) Mutagenesis i: G → A: It forces the apoenzyme to adopt the closed rather than the open conformation.

Reduces the binding affinity. 1 Publication, 1: Mutagenesis. In Escherichia coli, radiation and chemically inducible mutagenesis requires a functional umuC gene product. The umuC mutants are defective in mutagenesis and slightly sensitive to DNA damaging agents.

A chromosomal fragment that complemented the umuC mutations for UV mutability and UV resistance was cloned into miniF vector plasmid pMF3 by a shotgun method.

Escherichia coli and Salmonella typhimurium, Vols. I and II. Washington (D.C.): American Society of Microbiology.

Chapter 2. Tang M, Shen X, Frank EG, O'Donnell M, Woodgate R, et al. () UmuD′2C is an error-prone DNA polymerase, Escherichia coli Pol V. Proc Natl Acad Sci U S A – View Article. Growth media: E.

coli K strains were routinely grown in LB broth (Miller ). Tetracycline, chloramphenicol, and ampicillin, when required, were added to 15, 30, and mg/ml, respectively. Minimal medium employed 56/2 salts (Willetts et al. ), glucose, or lactose at % and % thiamine.

To visualize the Lac phenotype, X-gal. Escherichia coli NKJ (Saito et al., ) and NKJ (Shimamura et al., ) were used for mutagenesis experiments. NKJ is a derivative of AB (Howard-Flanders et al., ) and has the alleles Δ nth::Cm and Δ nei::Km.

SY5 is an F′-negative derivative of JM. Bacterial strains and plasmids. The E. coli K strain used for UV-survival and mutagenesis assays was RW, (full genotype: ΔumuDCermGT lexA51 (Def) recA thr-1 araD Δ(gpt-proA) 62 lacY1 tsx supE44 galK2 hisG4 rpsL31 xyl-5 mtl-1 argE3 thi-1 sulA).The low-copy-number plasmids used in this study are derived from pGB2 [].The three umuC substitutions.

In some enterobacterial pathogens, but not in Escherichia coli, loss-of-function mutations are a common route to clinically relevant β-lactam antibiotic resistance. We previously constructed an assay system for studying enterobacterial β-lactam resistance mutations using the well-developed genetics of E.

coli by integrating enterobacterial ampRC genes into the E. coli chromosome. :Vlulation Res., 9 (I97o) 2I 3 MUTAGENESIS IN Escherichia coli. 23 E. coli H/r 3o-R is an arginine auxotroph of the B family with the B/r phenotype which mutates to prototrophy by the formation of amber suppressors.

A number of radiation-sensitive nmtants have been isolated in the laboratory of Dr. KONDO. RpoS is a conserved alternative sigma factor that regulates the expression of many stress response genes in Escherichia coli.

The RpoS regulon is large but has not yet been completely characterized. In this study, we report the identification of over RpoS-dependent fusions in a genetic screen based on the differential expression of an operon- lacZ fusion bank in rpoS mutant and wild-type.

A high-throughput method has been developed for the systematic mutagenesis of the Escherichia coli genome. The system is based on in vitro transposition of a modified Tn 5 element, the Sce-poson, into linear fragments of each open reading frame.

The transposon introduces both positive (kanamycin resistance) and negative (I-SceI recognition site) selectable markers for isolation of mutants and.

Spontaneous and UV-induced mutations in Escherichia coli K strains with altered or absent DNA polymerase I Our data provide no evidence for a pathway of UV mutagenesis dependent on PolI. A rifampin-resistant ribonucleic acid (RNA) polymerase mutant, rifr51, derived from a presumptive RNA synthesis mutant of Escherichia coli K, complements rifr RNA polymerase mutants isolated.

Lac Repressor Experimental Mutagenesis Data • UCLA researchers (Jeffery H. Miller lab) introduced the same 13 amino acid substitutions at positions • non-degenerate single point mutants self-substitutions (control) • Full activity (> fold repression of β-galactosidase); moderate.

Mutation Research Elsevier Publishing Company, Amsterdam Printed in The Netherlands MUTATION TO PROTOTROPHY IN ESCHERICHIA COLI K-I2: EFFECT OF BROTH ON UV-INDUCED MUTATION IN STRAIN ABII57 AND FOUR EXCISION-DEFICIENT MUTANTS MICHAEL H. GREEN, M. ANNE ROTHWEI,L AND BRYN A. BRIDGES MRC Cell Mutation Unit, University of.

Escherichia coli (Kepes ML - lac I-Z + Y + A +) NCIMB and UV mutants were grown overnig ht in L.B. medium supplem ented with lactose soluti on with different conce ntrations (5%, 10%, 15 %. It has been shown that in alkB – mutants the level of MMS-induced mutagenesis depends on the test system used, and is several orders of magnitude higher when measured in the argE3→Arg + reversion test system in E.

coli AB in comparison to lacZ→Lac + reversion studied in CCCC strains (Nieminuszczy et al., a; b; The bacterial strains used in this study were derived from K and are listed in Table I.

Cells were grown at 37°C with shaking in Luria–Bertani (LB) medium (18). Overnight cultures were diluted 1: 40 in LB and grown until the exponential phase (∼2 × 10 8 cells/ml) for all experiments. L.L. Lin, J.W. LittleIsolation and characterization of noncleavable (Ind-) mutants of the LexA repressor of Escherichia coli K J.

Bacteriol., (), pp. CrossRef View Record in Scopus Google Scholar. Chromosomes are divided into topologically independent regions, called domains, by the action of uncharacterized barriers. With the goal of identifying domain barrier components, we designed a genetic selection for mutants with reduced negative supercoiling of the Escherichia coli chromosome.

We employed a strain that contained two chromosomally located reporter genes under the control of a. Recovery of aflatoxin B1-induced base substitution mutations in Escherichia coli was almost completely dependent on the presence of the SOS-mutagenesis-enhancing operon mucAB+; the normal E.

coli. Mutagenesis of Essential Genes: Conditional lethal mutants. Herring and F. Blattner (). "Conditional lethal amber mutations in essential Escherichia coli genes."J Bacteriol Amber mutations were introduced into essential genes using "Tagalong Mutagenesis".

@article{osti_, title = {Photoreactivation in phr mutants of Escherichia coli K}, author = {Husain, I. and Sancar, A.}, abstractNote = {We have investigated the genetics of photoreactivation in Escherichia coli K We found that strains with point mutations or deletions in the phr gene showed a significant residual level of photoreactivation after exposure to large fluences of.

The DinB (PolIV) protein of Escherichia coli participates in several cellular functions. We investigated a dinB mutation, Δ(dinB-yafN)(::kan) [referred to as ΔdinB], which strongly sensitized E.

coli cells to both UV- and X-radiation killing. Earlier reports indicated dinB mutations had no obvious effect on UV radiation sensitivity which we confirmed by showing that normal UV radiation. We isolated several new mutator mutations of the Escherichia coli replicative polymerase dnaE subunit alpha and used them and a previously reported dnaE mutation to study spontaneous frameshift and base substitution mutations.

Two of these dnaE strains produce many more mutants when grown on rich (Luria-Bertani) than on minimal medium. A differential effect of the medium was not observed when. Escherichia coli with different mutations at the same coding positioninthelacZgene,whichspecifiestheactivesite glutamic acid residue at position in .In Escherichia coli, the SOS response changes the expression of more than 40 genes: inducing some, while repressing others (Fernandez De Henestrosa et al., ; Courcelle et al., ).

Induction of SOS genes ranges from about three‐ to fivefold in the cases of uvrA, uvrB, uvrD, ruvAB and lexA to about ‐fold in the case of sulA.The lacI–Z gene fusion has a +1 frameshift in lacI, adding a G:C base pair to a run of three G:C base pairs, resulting in a Lac – phenotype (Calos and Miller, ).

During non‐selective growth, Lac + mutants of FC40 arise at a rate of about 10 −9 per cell per generation.