Dissertations / Theses: 'DNA Polymerase III'

1

Lee, Sally. "Architecture of RNA polymerase II and RNA polymerase III pre-initiation transcription complexes /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/9213.

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2

Varshney, Dhaval. "Regulation of RNA polymerase III transcription by DNA methylation and chromatin." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3114/.

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Mammalian genomes contain huge numbers of short interspersed elements (SINEs). An extreme case is provided by the human genome, which carries ~106 copies of Alu SINEs that together account for ~10% of total chromosomal DNA. SINEs spread by retrotransposition, which depends on their transcription by pol III. This transcription is heavily suppressed. Silencing is thought to involve DNA methylation and packaging the SINEs into chromatin structures that deny access of transcription factors. It has been argued that this may be of great importance to prevent SINEs from competing with essential genes for a limited pool of transcription machinery. Our investigation of this has revealed some unexpected findings. This study has also investigated the effects of SWI/SNF chromatin remodellers on tRNA transcription.

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3

Allison, Simon J. "Regulatory studies of the mammalian RNA polymerase III transcriptional apparatus." Thesis, University of Glasgow, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343976.

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4

Isoz, Isabelle. "Role of yeast DNA polymerase epsilon during DNA replication." Doctoral thesis, Umeå : Umeå University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1932.

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5

Slater, Steven Charles. "The role of DNA polymerase III in DNA repair and mutagenesis in Escherichia coli and Salmonella typhimurium." Case Western Reserve University School of Graduate Studies / OhioLINK, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=case1057261938.

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6

Colbert, Trenton. "Characterization of BRF1, an RNA polymerase III transcription factor /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/6320.

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7

Pacitti, Diane Frances. "The Characterization of Staphylococcus Aureus polC: the Structural Gene for DNA Polymerase III." eScholarship@UMMS, 1995. http://escholarship.umassmed.edu/gsbs_diss/271.

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The major research interest of our laboratory is focused on the replication-specific DNA polymerase III (pol III) family in Gram+ bacteria, and has used Bacillus subtilis (BS) as the primary model enzyme for study. The long range objective of the work of the laboratory is to gain a deeper understanding of the structure and function of Gram+ bacterial DNA polymerase IIIs, a structurally unique class of DNA-dependent DNA polymerase which are uniquely susceptible to inhibition by a specific class of dGTP analogs. The project described in this thesis dissertation deals specifically with the pol III of the Gram+ organism Staphylococcus aureus, and involves the isolation and characterization of DNA pol III from this clinically relevant pathogenic bacterium. A homology-based strategy was devised to clone the structural gene specifying DNA polymerase III of Staphylococcus aureus, SA polC. SA polC was found to contain a 4305-bp open reading frame (ORF) encoding a 162.4 kDa polypeptide, and mapped between Ω1074[Tn551] and recA/ngr on the genome map of S. aureus NCTC 8325. The 1435 codon ORF was engineered into the E. coli expression plasmid pBS(KS) under the control of the lac promoter and its repressor. The translational signals of SA polC were reengineered using expression cassette PCR (ECPCR) to optimize the in vitro expression of SA polC in E. coli. Derepression of E. coli transformants carrying the recombinant vector generated high level expression of active recombinant pol III. The recombinant SA pol III was purified to greater than 98% homogeneity and was shown by N-terminal amino acid analysis to be the bona fide product of the 4305-bp SA polC ORF. The physical and catalytic properties of recombinant SA pol III and its responsiveness to inhibitors of the HPUra type were similar to those of Bacillus subtilis (BS) pol III. Comparative structural analysis of the primary structure of SA pol III and the pol IIIs of B. subtilis and the Gram+ relative Mycoplasma pulmonis indicated strong conservation of essential catalytic domains and a novel zinc-finger motif. Comparison of the primary structures of E. coli pol III and these three Gram+ enzymes suggested a specific evolutionary relationship between the pol IIIs of Gram+ and Gram- bacteria.

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8

Lancy, Edward Donald Jr. "Genetic requirements for growth of Salmonella typhimurium lacking the proofreading subunit of DNA polymerase III." Case Western Reserve University School of Graduate Studies / OhioLINK, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=case1054846339.

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9

Sabouri, Nasim. "Structure of eukaryotic DNA polymerase epsilon and lesion bypass capability." Doctoral thesis, Umeå : Univ, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1477.

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10

Hög, Friederike. "Functional studies of RNA polymerase II recruitment to promoter DNA and impact of BRF1 mutations on RNA polymerase III-dependent transcription." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-179326.

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11

Tarantino, Paul M. "Development of the Antibiotic Potential of a Unique Family of DNA Polymerase Inhibitors." eScholarship@UMMS, 1998. https://escholarship.umassmed.edu/gsbs_diss/311.

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The work in the Brown laboratory has two long-range objectives. Both are derived from an interest in the replication of the genome of Gram-positive eubacteria. One objective is to gain a deeper understanding of the structure and function of DNA polymerase III, the unique species of DNA polymerase which is essential for chromosome replication. The second objective, the one from which this thesis is derived, is to determine whether a selective inhibitor of this DNA polymerase can serve as a basis for producing a new generation of clinically useful Gram-positive-selective antimicrobial agents. The polymerase III-specific inhibitor prototypes investigated in this work are members of a family of simple 6-substituted uracils. The following members of this family, TMAU and EMAU, were used as platforms for the manipulation of the N3 atom (arrow), the only ring component which could be substituted without severe reduction of inhibitory activity. The N3 position was substituted with a series of alkyl groups of increasing size. The resulting structure-activity relationships at the level of the polymerase was consistent with the presence of an N3-specific subdomain within the inhibitor binding site which could accommodate a wide variety of substituents. Although specific alkyl substituents at N3 also significantly enhanced the antibacterial potency of TMAU and EMAU, the respective compounds were found to have insufficient aqueous solubility for successful application in in vivo infection. To increase aqueous solubility, the N3 atom of the EMAU platform was substituted with selected hydroxy- and methoxyalkyl groups. The latter agents retained both anti-polymerase and antibacterial activity, and, as expected, they displayed a combination of lipid and aqueous solubility favorable to efficacy in in vivo infection. Two of the agents, N3-hydroxypropyl- and N3-methoxypropyl-EMAU were examined for their ability to protect mice from lethal staphylococcal infection. Both were found to be active in this model. In sum, the results of this work demonstrated, for the first time, that: (1) the eubacterial replication-specific DNA polymerase III is a valid target for antibiotic development, and (2) the N3-substituted 6-anilinouracil platform has strong potential as a basis for novel antibiotics useful against Gram-positive bacterial infection.

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12

Hög, Friederike [Verfasser], and Patrick [Akademischer Betreuer] Cramer. "Functional studies of RNA polymerase II recruitment to promoter DNA and impact of BRF1 mutations on RNA polymerase III-dependent transcription / Friederike Hög. Betreuer: Patrick Cramer." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1067055290/34.

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13

Butler, Michelle Marie. "Probing the dNTP Binding Region of Bacillus subtilis: DNA Polymerase III with Site-Directed Inhibitors: A Dissertation." eScholarship@UMMS, 1992. https://escholarship.umassmed.edu/gsbs_diss/132.

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6-(p-Hydroxyphenylhydrazino) uracil (H2-HPUra) is a selective and potent inhibitor of the replication-specific DNA polymerase III (pol III) of Gram+ bacteria such as Bacillus subtilis. Although a pyrimidine, H2-HPUra derives its inhibitory activity from its specific capacity to mimic the purine nucleotide, dGTP. The project described in this thesis dissertation involves the use of H2-HPUra-like inhibitors to probe the structure and function of the pol III active site. It consists of two separate problems which are summarized below. Production of a potent bona fide dGTP form of inhibitor. A method was devised to successfully convert the H2-HPUra inhibitor prototype to a bona fide purine, using N2-benzyl guanine as the basis. Structure-activity relationships of benzyl guanines carrying a variety of substituents on the aryl ring identified N2-(3,4-dichlorobenzyl) guanine (DCBG) as a compound equivalent to H2-HPUra with respect to potency and inhibitor mechanism. DCBdGTP, the 2'-deoxyribonucleoside 5'-triphosphate form of DCBG, was synthesized and characterized with respect to its action on wild-type and mutant forms of pol III. DCBdGTP acted on pol III by the characteristic inhibitor mechanism and formally occupied the dNTP binding site with a fit which permitted its polymerization. The latter experiment identified the site for the binding of the inhibitor's aryl moiety as a distinct site located at a distance of approximately 6-7 Å from the base-paired 2-NH group of a bound dGTP. Attempt to covalently label amino acid residue 1175, a putative participant in inhibitor binding. Azp-12, a point mutation of serine 1175, yields a form of pol III whose inhibitior sensitivity varies specifically as a function of the composition of the para substituent of the inhibitor's aryl ring. On the basis of the latter behavior, residue 1175 was hypothesized to be a residue directly involved in the binding of the inhibitor's aryl moiety. To test this hypothesis, residue 1175 was specifically mutated to either cysteine or lysine, each of which presents a side chain amenable to covalent bond formation with appropriately reactive inhibitor forms. Of the two mutant pol III forms, only the cysteine form (pol III-cys) was catalytically active. The kinetic properties and inhibitor sensitivity profile of pol III-cys identified it as a target suitable for potentially irreversible inhibitor forms containing the following groups in the meta position of the aryl ring: -CH2Br, -CH2C1, and -CH2SH. None of the several inhibitors tested selectively or irreversibly inactivated pol III-cys. Possible bases for the failure of this group of inhibitors and for the redesign of more useful covalently reactive inhibitor forms are considered.

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14

Marchetti, Alessandro. "Sviluppi metodologici per la cristallizzazione e l’analisi strutturale di proteine tramite Risonanza Magnetica Nucleare allo stato solido." Doctoral thesis, Scuola Normale Superiore, 2012. http://hdl.handle.net/11384/85789.

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High-resolution solid-state NMR (ssNMR) has recently emerged as a powerful characterization technique for systems that cannot be investigated by solution NMR or X-ray crystallographic methods, and represents a subtle complementary technique for any atomic-scaled study. This is particularly true in structural biology. There exist nowadays well established protocols for sample preparation, resonance assignment and collection of structural restraints, that have paved the way to the first three-dimensional structure determinations at atomic resolution of biomolecules in the solid state, from microcrystalline samples to fibrils and membrane-associated systems. Despite rapid uptake in the field of structural biology, however, these methods for structure determination are far from being routine, and several important problems remain however to be solved before ssNMR is applied to the study of challenging solid protein assemblies. Many methodological developments are still expected in this fast evolving field. Most of the model systems used up-to-date for method development in biological solid-state NMR, are relatively small globular proteins, in the range of 50 to 80 residues (approximately 5.5 to 9.5 kDa). In order to extend the capabilities of ssNMR to larger substrates, the objectives of this thesis are twofold: a) to establish a new, large and more complex model system, and b) to develop new, sophisticated NMR experiments in order to improve the sensitivity and the resolution of the currently existing schemes for resonance assignment, which is one of the main barrier to progress to structural investigation in solid proteins. The N-terminal domain of the subunit of E. coli DNA polymerase III (186 : 186 residues, 18 kDa) was selected as a target. This domain represents the catalytic core of the E. coli replisome, the large molecular machine that replicated DNA in bacteria. In a first part, preparation conditions for solid-state NMR are obtained, notably in combination with automated screening processes for high-throughput protein crystallography, and almost complete resonance assignment is performed by the application of established experiments based on high-power rf irradiations and slow magic-angle spinning (MAS) at high magnetic fields. In a second part, we explore the use of MAS at so-called ultra-fast spinning rates (60 kHz). We show that this makes possible the use of “totally low power” experiments. This yields an extraordinary increase in resolution and sensitivity, enabling the acquisition of selective cross- polarization (CP) transfers, through-bond correlations and 1 H-detected correlations. In particular, we demonstrate that narrow 1 H NMR line widths can be obtained for fully protonated protein samples in the solid state under ultra-fast magic-angle spinning for medium-size microcrystalline and non-crystalline proteins, without any need for dilution against a deuterated background. This provides extensive, robust and expeditious assignments of the backbone 1 H, 15 N, 13 Cα and 13 CO resonances of proteins in different aggregation states, without the need of deuteration. The final part of this thesis concerns the study of thermotropic liquid crystals (LC or LX) phases of a de Vries smectogen, the (S)-hexyl-lactate derivative abbreviated as 9HL, selectively deuterated in a phenyl moiety of the aromatic core. de Vries mesophases show a substantially constant layer spacing in the transition between smectic C and smectic A mesophases and are for this reason of great interest for the development of new ferroelectric (FLC) and antiferroelectric (AFLC) electrooptic devices. Our work is the first attempt to apply NMR to characterize the nature of the de Vries transition, discriminating among possible models. It is also one of the first examples in the scientific literature of application of high magnetic field (above 16 T) for the analysis of LX phases.

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15

Berry, Noémie. "Le stress mitochondrial induit par le Virus de l’Herpès Simplex de type 1 entraîne la surexpression de la cytidine désaminase APOBEC3A." Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS185.

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L’ADN cytosolique constitue un signal de danger pour la cellule. L’ADN mitochondrial (ADNmt) en tant que DAMPs stimule les senseurs à ADN et induit la production de cytokines pro-inflammatoires (interférons). La cytidine désaminase humaine APOBEC3A (A3A), sensible à une réponse IFN, induit la désamination des cytidines en uraciles dans l’ADN simple brin entraînant la dégradation de l’ADN muté et l’extinction du signal de danger. Dans une première partie, nous avons montré le rôle de la voie de signalisation ARN polymérase III / RIG-I dans la détection de l’ADNmt et la surexpression d’A3A en réponse à la production d’IFN I. Nous avons confirmé que A3A induit le catabolisme de l’ADNmt cytosolique en entraînant cependant des mutations de type GC vers AT et des cassures double-brin dans le génome nucléaire. La seconde partie a mis en évidence dans un modèle cellulaire humain que le Virus de l’Herpès Simplex de type 1 (VHS-1) entraîne un relargage d’ADNmt. Une fragmentation du réseau mitochondrial semble être à l’origine de ce relargage qui s’accompagne d’une production d’IFN I et d’une surexpression de A3A. Si nous avons confirmé le rôle de la voie ARN polymérase III / RIG-I, il semble que la voie de signalisation cGAS-STING soit aussi impliquée. Ces travaux ont donc montré dans un modèle humain que le stress mitochondrial induit par le VHS-1 contribue à la surexpression de A3A
The presence of DNA in the cytosol represents a danger signal. Mitochondrial DNA (mtDNA) has been recognized as a DAMP (damage-associated molecular-pattern molecule), able to induce the production of pro-inflammatory cytokines (interferons). The human cytidine deaminase APOBEC3A (A3A), upregulated by IFN, catalyzes the deamination of cytidine to uridine in single stranded DNA substrates leading to the catabolism of the mutated DNA sequence and the suppression of the signal. First, we demonstrated the role of the RNA polymerase III / RIG-I signaling in the upregulation of A3A expression in response to IFN production. We also confirmed the mtDNA catabolism induced by A3A. However, its overexpression leads to GC vers AT mutations and double-strand DNA breaks in the nuclear genome. The second part of my thesis highlighted the release of mtDNA within the cytosol upon Herpes Simplex Virus Type 1 (HSV-1) infection in a human cellular model, probably triggered by a fragmentation of the mitochondrial network. We demonstrated that this mtDNA release is associated with a strong production of IFN and the overexpression of A3A. While we confirmed the role of the RNA polymerase III / RIG-I signaling, the cGAS-STING pathway should be also involved. Finally, in this thesis, we have shown in a human model that the mitochondrial stress induced by HSV-1 contributes to the overexpression of A3A

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16

Monton, Silva Alejandro <1988&gt. "Structural and kinetic characterization of DNA polymerases I and III from Escherichia coli." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6794/1/MontonSilva_Alejandro_tesi.pdf.pdf.

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DNA elongation is performed by Pol III α subunit in E. coli, stimulated by the association with ε and θ subunits. These three subunits define the DNA Pol III catalytic core. There is controversy about the DNA Pol III assembly for the simultaneous control of lagging and leading strands replication, since some Authors propose a dimeric model with two cores, whereas others have assembled in vitro a trimeric DNA Pol III with a third catalytic core, which increases the efficiency of DNA replication. Moreover, the function of the PHP domain, located at the N-terminus of α subunit, is still unknown. Previous studies hypothesized a possible pyrophosphatase activity, not confirmed yet. The present Thesis highlights by the first time the production in vivo of a trimeric E. coli DNA Pol III by co-expressing α, τ, ε and θ subunits. This trimeric complex has been enzymatically characterized and a molecular model has been proposed, with 2 α subunits sustaining the lagging-strand replication whereas the third core replicates the leading strand. In addition, the pyrophosphatase activity of the PHP domain has been confirmed. This activity involves, at least, the H12 and the D19 residues, whereas the D201 regulates phosphate release. On the other hand, an artificial polymerase (HoLaMa), designed by deleting the exonuclease domain of Klenow Fragment, has been expressed, purified and characterized for a better understanding of bacterial polymerases mechanism. The absence of exonuclease domain impaired enzyme processivity, since this domain is involved in DNA binding. Finally, Klenow enzyme, HoLaMa, α subunit and DNA Pol III αεθ have been characterized at the single-molecule level by FRET analysis, combining ALEX and TIRF microscopy. Fluorescently-labeled DNA molecules were immobilized, and changes in FRET efficiency enabled us to study polymerase binding and DNA polymerization.

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17

Monton, Silva Alejandro <1988&gt. "Structural and kinetic characterization of DNA polymerases I and III from Escherichia coli." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6794/.

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DNA elongation is performed by Pol III α subunit in E. coli, stimulated by the association with ε and θ subunits. These three subunits define the DNA Pol III catalytic core. There is controversy about the DNA Pol III assembly for the simultaneous control of lagging and leading strands replication, since some Authors propose a dimeric model with two cores, whereas others have assembled in vitro a trimeric DNA Pol III with a third catalytic core, which increases the efficiency of DNA replication. Moreover, the function of the PHP domain, located at the N-terminus of α subunit, is still unknown. Previous studies hypothesized a possible pyrophosphatase activity, not confirmed yet. The present Thesis highlights by the first time the production in vivo of a trimeric E. coli DNA Pol III by co-expressing α, τ, ε and θ subunits. This trimeric complex has been enzymatically characterized and a molecular model has been proposed, with 2 α subunits sustaining the lagging-strand replication whereas the third core replicates the leading strand. In addition, the pyrophosphatase activity of the PHP domain has been confirmed. This activity involves, at least, the H12 and the D19 residues, whereas the D201 regulates phosphate release. On the other hand, an artificial polymerase (HoLaMa), designed by deleting the exonuclease domain of Klenow Fragment, has been expressed, purified and characterized for a better understanding of bacterial polymerases mechanism. The absence of exonuclease domain impaired enzyme processivity, since this domain is involved in DNA binding. Finally, Klenow enzyme, HoLaMa, α subunit and DNA Pol III αεθ have been characterized at the single-molecule level by FRET analysis, combining ALEX and TIRF microscopy. Fluorescently-labeled DNA molecules were immobilized, and changes in FRET efficiency enabled us to study polymerase binding and DNA polymerization.

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18

Crowther, Jeffrey Andrew. "Subunits of Escherichia coli DNA polymerase III holoenzyme." Phd thesis, 2000. http://hdl.handle.net/1885/148631.

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19

Thompson, Phillip Raymond. "Subunits of DNA polymerase III holoenzyme of Escherichia coli." Phd thesis, 1992. http://hdl.handle.net/1885/144149.

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20

Jergic, Slobodan. "Structure and function of E. coli DNA polymerase III holoenzyme." Phd thesis, 2006. http://hdl.handle.net/1885/151632.

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21

Yang, Ji Yeon. "Aspects of core subunits of DNA polymerase III holoenzyme in Escherichia coli." Master's thesis, 1997. http://hdl.handle.net/1885/144293.

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22

Shu, Hung-Wei, and 許紘瑋. "Evolution of the duplicated subunit genes of DNA polymerase III in Actinomycetes." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/15577668344039218457.

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碩士
國立陽明大學
醫學生物技術研究所
95
DNA polymerase III (Pol III) is a multi-subunit enzyme that replicates bacterial chromosomes. Most Actinomycetes chromosomes contain more than one copy of genes encoding some Pol III subunits, particularly the α (dnaE; catalytic subunit) and ε (dnaQ; 3’→5’ exonuclease) subunits. The duplicated dnaE genes in M. tuberculosis and C. crescentus have been found to be involved translesion repair. Most other bacteria contain only single copy of genes for the Pol III subunits. Firmicutes contain, in addition to DnaE, a different catalytic enzyme, PolC, and each of these is specifically responsible for the replication of the two DNA strands. Other than these, little is know about the functions of the duplicated Pol III subunits. In this thesis, I studied the evolution of the duplicated Pol III subunit genes in Actinomycetes using bioinformatic and phylogenetic analyses, and attempted to investigate the role of a duplicated dnaE gene in Streptomyces by gene knockout experiments. The phylogenetic analysis clearly separate the DnaE homologs into a essential clade (designated DnaE1), which include those present uniquely in most other bacteria, and another (designated DnaE2), which are found in bacteria with duplication. Based on the accepted branching order of bacteria, the duplication of dnaE genes was determined to occur on the main trunk of the phylogenetic tree between the branching of Firmicutes and Actinomycetes. Analysis of synonymous vs synonymous substitutions (Ka/Ks ratio) and the relative rate tests show that dnaE2 in Actinomycetes has experienced more relaxed selection (particularly in the thumb domain and, in Streptomyces, the PHP domain) and evolved rapidly after the duplication. The dnaE2 gene in Streptomyces coelicolor was successfully knocked out by targeted mutagenesis. The mutants, unlike those in M. tuberculosis and C. crescentus, did not show increased sensitivity to ultraviolet radiation. Thus, dnaE2 in Streptomyces is probably not involved in repair. Furthermore, their chromosomes of the mutants remained linear, indicating that dnaE2 is not required for replication of the linear chromosomes. The evolution of the ε subunit in Actinomycetes appears to be more complicated involving multiple rounds of duplications, deletions and/or lateral gene transfer during evolution. The three ε subunits in the Actinomycetal ancestor appear to retain the same function, and the duplication may be serve to provide genetic robustness against null mutations or to provide the proof-reading activities to different catalytic DNA polymerases.

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23

Whatley, Zakiya Nicole. "Involvement of a DNA Polymerase III Subunit in the Bacterial Response to Quinolones." Diss., 2014. http://hdl.handle.net/10161/8773.

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Quinolone treatment induces stabilized cleavage complexes (SCCs), consisting of a covalent gyrase-DNA complex, and processing of these complexes is thought to cause double-strand breaks and chromosome fragmentation. SCCs are required but not sufficient for cytotoxicity; the mechanism that converts SCCs to double-strand breaks is not clearly understood. Evidence of chromosome fragmentation due to quinolones comes from indirect measures such as sedimentation analysis of nucleoids and measurements of lysis viscosity. This work outlines a method that combines agarose plugs, conditional lysis and field inversion gel electrophoresis to allow direct visualization of chromosomal fragmentation resulting from quinolone treatment. We are able to distinguish between latent breaks within the stabilized cleavage complex and irreversible breaks that result from downstream processing.

When seeking to understand the genetic requirements for quinolone-induced SOS response, we found that a dnaQ mutant has a specific defect in SOS induction following nalidixic acid. The product of dnaQ is the ε subunit of DNA polymerase III, which provides 3' → 5' exonuclease activity. In addition to the nalidixic acid-specific SOS defect, δdnaQ has multiple phenotypes: slow growth, high mutation frequency, and constitutive SOS. We propose that ε has a role in the quinolone response beyond the normal proofreading function of the subunit in the polymerase III core. Using a unique transposon mutagenesis system, we created a library of dnaQ mutants with 15 base pair insertions that were scored phenotypically. We identified mutants that separated the various phenotypes, arguing strongly that ε has multiple functions. The isolation of a stable dnaQ mutant with SOS phenotypes allows the study of this function without confounding results from spurious mutations throughout the chromosome. We also isolated a novel class of SOS "hyper-inducible" mutants. Additionally, my findings with weak and strong β-clamp binding mutants provides the first in vivo characterization of these ε mutants and gives insight into the SOS response following nalidixic acid treatment.

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24

Tang, Tien-Jen, and 唐天仁. "Cloning of the Gene Coding for DNA Polymerase III of Phytoplasma Associated with Peanut Witches' Broom." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/38319084997153695723.

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25

Park, Ah Young. "Structure and function of the proofreading exonuclease subunit of E. coli DNA polymerase III and related enzymes." Phd thesis, 2006. http://hdl.handle.net/1885/148475.

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Dissertations / Theses on the topic 'DNA Polymerase III'

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