<p>Aluminum-Silicon (Al-Si) alloys are often preferred in the die casting industry due to excellent castability, high strength, corrosion resistance and low cost. Commonly, iron (Fe) is alloyed with the alloys to prevent die soldering. However, the addition of Fe in most of Al-Si alloys leads to formation of the intermetallic β-AlFeSi. The β-AlFeSi is harmful to the alloy structural integrity due to its needle-like morphology that creates stress concentration at the microscopic level. The phase presence is unfavorable to the mechanical properties and significantly reduces the elongation of the alloys. This research attempted to find viable way to control the morphology and formation of the β-AlFeSi phase.</p> <p>Thermodynamic simulations were done to investigate the sequence of intermetallic formation and other phases at different alloy compositions. The analysis of solidification paths of different alloys provided the correlation between the phase formation sequence and the fraction of the β-AlFeSi phase. The analysis also identified the feasible region of alloy design for minimizing the β-AlFeSi formation. Based on the thermodynamics simulation analysis, five alloys of different compositions were designed to validate the finding of the simulation. </p> <p>The tensile test results of the alloys indicated that lowering the Fe content increases the elongation of the alloy. The results also showed that elongation was reduced with the increase of Si level due to the formation of eutectic Silicon. The change of both Fe and Mn did not significantly affect the mechanical property of the alloy when the ratio of Fe to Mn was constant. Microscopic analysis showed that lowering the Fe level had effectively altered the morphology of the β-AlFeSi needle like structure. The β-AlFeSi was found to be smaller in terms of size when Fe is lower, subsequently reducing the probability of β-AlFeSi phase to be stress riser and crack initiation. </p> <p>The influence of heat treatment to the mechanical property of the alloys was also studied. The mechanical result on the heat-treated samples indicated that heat treatment is a viable method to improve the elongation property of the alloy. Microscopic observations showed that the β-AlFeSi phase was broken into shorter structures over the solution heat treatment process, resulting in better elongation. </p>

Genexpression in Eukaryoten beschreibt einen mehrstufigen Prozess, welcher auf Ebene der Transkription durch den positiven Transkriptionselongationsfaktor P-TEFb entscheidend reguliert wird. PTEFb bildet einen heterodimeren Komplex aus der Cyclin abhängigen Kinase 9 und deren Kofaktor Cyclin T1/2. Dieser Komplex aktiviert die Elongation der Transkription durch Phosphorylierung der negativen Elongationsfaktoren DSIF und NELF. Darüber hinaus phosphoryliert PTEFb Serin2 Reste in der C-terminalen Domäne von RNA PolII und stimuliert so die kotranskriptionelle Prozessierung der synthetisierten prä-mRNA. In Anpassung an unterschiedliche Wachstumsbedingungen wird die Aktivität dieses Faktors durch reversible Interaktion mit 7SK RNA und HEXIM Proteinen innerhalb eines katalytisch inaktiven Ribonukleoproteinpartikels (7SK RNP) streng kontrolliert. Dieses sensible Gleichgewicht zwischen P-TEFb auf der einen und dem 7SK RNP auf der anderen Seite bildet die Grundlage der Regulation der Transkriptionselongation. Trotz der hohen Abundanz von 7SK RNA in der Zelle, assoziiert in vivo jedoch nur ein relativ kleiner Teil hiervon mit P-TEFb, sodass die effektiv zur Verfügung stehende RNA-Menge für die Bildung des 7SK RNP vermutlich limitierend wirkt. Ziel der vorliegenden Arbeit war es daher neue 7SK RNA interagierende Faktoren zu identifizieren, welche die Interaktion von PTEFb mit dem 7SK RNP steuern und so die PolII abhängige Transkription regulieren. Anhand verschiedener chromatographischer Reinigungen konnte zunächst ein bislang uncharakterisiertes La ähnliches Protein (LARP7) mit einer spezifischen Affinität für Pyrimidinreiche RNAs isoliert werden. LARP7 bindet, wie durch immunbiochemische Analysen und RNA- Bindungsstudien gezeigt werden konnte, quantitativ an das hoch konservierte uridylreiche 3´- Ende von 7SK RNA. Diese Assoziation erfordert dessen La- und RRMDomänen und erhöht wesentlich die Stabilität der RNA. Darüber hinaus kofraktioniert LARP7 mit weiteren Faktoren des 7SK RNP, bindet direkt an HEXIM1 und P-TEFb und stellt somit ebenfalls eine integrale Komponente des 7SK RNP dar. Die gewonnenen Daten weisen außerdem erstmals darauf hin, dass P-TEFb durch einen vorgeformten trimeren Komplexes, bestehend aus HEXIM1, 7SK RNA und LARP7 inhibiert wird. Reportergenanalysen in TZMbl-Zellen, welche Luziferase unter der Kontrolle des streng P-TEFb abhängigen HIV-1-LTRPromotors exprimieren zeigten, dass diese Inhibition im Wesentlichen durch LARP7 vermittelt wird. So ließ sich nach Reduktion der LARP7 Expression mittels RNAi eine signifikante Steigerung der Transkription vom HIV-1-LTR-Promotor beobachten. Eine ähnliche Stimulation der Transkription von PolII konnte in LARP7 defizienten HeLa-Zellen durch quantitative Real-Time-PCR auch für eine Reihe zellulärer Gene nachgewiesen werden. Die Beobachtung, dass LARP7 die generelle PolII Transkription reprimiert, korreliert zudem mit einer bereits beschriebenen Tumorsupressorfunktion des LARP7 homologen mxc Proteins aus D. melanogaster. Somit beeinflusst LARP7 das zelluläre Gleichgewicht zwischen freiem und 7SK RNP-gebundenem P-TEFb und fungiert somit als negativer Regulator der PolII Transkription in vivo. / Eucaryotic gene expression is a multistep process, which is critically regulated on the level of RNA polII transcription by the positive transcription elongation factor P-TEFb. P-TEFb forms a heterodimeric complex, consisting of the cyclin-dependent kinase 9 and its cofactor cyclin T1/2. This complex stimulates transcriptional elongation as well as the cotranscriptional processing of the synthesized pre-mRNA by phosphorylation of negative elongation factors and the RNA polII Cterminal domain. To accommodate different growth conditions, P-TEFb activity is kept under tight control through its reversible interaction with 7SK RNA and HEXIM proteins in a catalytically inactive ribonucleoprotein particle (RNP). This sensitive balance between PTEFb on the one hand and the 7SK RNP on the other represents the basis of transcriptional regulation of elongation. Despite the high abundance of 7SK RNA in the cell, only a small part is associated with P-TEFb in vivo, suggesting that the actual amount of RNA available limits the formation of the 7SK RNP. Hence, the objective of the present study was to identify novel 7SK RNA interacting factors, which direct the interaction of P-TEFb with the 7SK RNP, thereby regulating polII dependent transcription. At first, using different chromatographic purification strategies, an as yet uncharacterized La related protein (LARP7) with an affinity to pyrimidine- rich RNAs was isolated. Immunobiochemical analysis and RNA binding studies revealed, that LARP7 quantitatively associates with the highly conserved 3´-UUU-OH terminus of 7SK RNA. This binding requires its La- and RRM-domain and dramatically increases RNA stability. Moreover, LARP7 co-fractionates with additional factors of the 7SK RNP, binds directly to HEXIM1 and P-TEFb and therefore likewise constitutes an integral component of the 7SK RNP. Data presented here indicate that P-TEFb is inhibited upon association with a trimeric complex consisting of HEXIM1, 7SK RNA and LARP7. Furthermore, reporter gene analysis in TZMbl cells - cells expressing luciferase under the control of the strictly P-TEFb dependent HIV-1-LTR promoter - demonstrated this inhibition to be mainly mediated by LARP7. Thus, reduction of LARP7 expression by RNA-interference led to a significant stimulation of transcription in TZMbl cells. In addition, quantitative real time pcr revealed a similar effect on transcription for a series of cellular genes in LARP7 deficient HeLa cells. Moreover, the observation, that LARP7 represses polII transcription in general correlates well with a known function of the d. melanogaster LARP7 homologue mxc as a tumor suppressor. Thus, LARP7 affects the cellular P-TEFb/7SK RNP equilibrium und serves as a negative regulator of polII transcription in vivo.

In mammals, there are two isoforms of eukaryotic translation elongation factor 1A (eEF1A) called eEF1A1 and eEF1A2. They share 98% similarity at the amino acid level, and the main function of both is to facilitate the elongation process in protein translation. However, they have very different expression patterns. While eEF1A1 is universally expressed, eEF1A2 is strictly expressed in muscle, brain and heart. The over-expression of eEF1A2 has been found in cancers, such as ovarian and breast cancer. The factors influencing the different expression patterns of the two isoforms and the mechanisms by which eEF1A2 can act as an oncogene are not clear, therefore, the main aim of this study was to further investigate these two areas. The first aim was to find out whether the resveratrol induced down-regulation of eEF1A2 was mediated by miR-663. Western blotting in MCF7 cells showed that the level of endogenous eEF1A2 was decreased after resveratrol treatment while eEF1A1 remained stable. In contrast, NIH-3T3 stable cell lines which stably express the eEF1A2 coding sequence (CDS) only did not show this down-regulation, suggesting that the untranslated regions (UTRs) might play a role in this regulation. I then showed that miR-663 has ability to down-regulate a reporter linked to the UTRs of eEF1A2. The same reporter gene harbouring UTRs in which the binding sites of miR-663 had been deleted also showed down-regulation after resveratrol treatment, suggesting that the UTRs of EEF1A2 are key to the down-regulation of eEF1A2 by resveratrol but that miR-663 does not mediate this decrease. The second project aimed to address why eEF1A2 is an oncogene but eEF1A1 is not. The 3D structure of human eEF1A1 and eEF1A2 shows that the most of the highly conserved amino acids differences between the two isoforms are Ser and Thr residues, which are potential sites for phosphorylation. I mutated these three sites in eEF1A2 expression constructs to the equivalent amino acid from eEF1A1. Firstly, by transient transfection, all the mutant eEF1A2 were shown expressed and the sub-cellular locations of eEF1A2 remain unchanged after site-directed mutagenesis. Then, stable cell lines were generated. Anchorage independent growth (soft agar) and focus formation assays showed that the stable cell lines harbouring wild type eEF1A2 were significantly more transformed that those expressing the eEF1A2 mutants. However, there was no apparent difference in global protein synthesis between these cell lines. The results suggest that the potential phosphorylated sites in eEF1A2 play an important role in its oncogenicity and that this oncogenicity is not related to the canonical function of eEF1A2.

Eukaryotic Elongation Factor 1A (eEF1A) exists in two forms in vertebrates. The first form, eEF1A1, is expressed ubiquitously throughout development but is downregulated postdevelopmentally and replaced with eEF1A2, an isoform sharing 92% amino acid identity, in neurons and muscle. The primary function of eEF1A is to recruit amino-acylated tRNAs in a GTP-dependent manner to the A site of the ribosome during protein translation, but it also has non-canonical roles in the cell, some of which are isoform dependent. The reasons for the cell-type dependent switch from eEF1A1 to eEF1A2 are poorly understood. The first aim of this project was to examine the role played by eEF1A isoforms in neuritogenesis. To do this I used RNAi to significantly reduce expression of one or other isoform in neuronal cells and measure the effects this had on neurite outgrowth. Neurite outgrowth was significantly reduced in cells depleted of eEF1A1, but not eEF1A2. The complete loss of eEF1A2 is fatal, as has been demonstrated in the wasted mouse, an eEF1A2-null model characterised by muscle wastage, neurodegeneration and death at 4 weeks of age. Mice heterozygous for the wasted mutation have normal motor function. Recent work has found that heterozygous missense mutations in eEF1A2 can cause epilepsy and intellectual disability. It is not yet known whether the seven different de novo mutations identified to date confer loss or gain of function – a crucial piece of information required before possible treatments can be sought. The second aim of this project therefore was to investigate the role of eEF1A2 in epilepsy and intellectual disability. I achieved this by using CRISPR in two ways; firstly to model one of the mutations, D252H, in vitro in a neuronal cell line, and secondly to model another of the mutations, G70S, in vivo. No mice that recapitulated the human disease condition of EEF1A2G70S/+ were obtained however, due to the error-prone nature of the non-homologous end joining repair pathway activated by CRISPR-mediated DNA cleavage, 17 of the 35 mice born were found to be homozygous nulls at the Eef1a2 locus. Nine of these had fatal audiogenic seizures caused by sudden loud noises within the animal unit. Three mice were Eef1a2G70S/- and one Eef1a2G70S/G70S but these nonetheless showed a wasted phenotype, indicating that this mutant form of eEF1A2 has compromised function, at least in terms of translation elongation. Whether it has a toxic function ca not yet be known, but the severity of the phenotype in the G70S homozygous animal could suggest a gain of function. In in vitro experiments with exogenous eEF1A2 carrying the epilepsy-causing mutation R423C, protein expression of the mutant construct in immortalised cell lines was significantly higher when cotransfected with the wildtype construct, which mirrors the condition in humans, than when transfected alone, so the mutant protein could be stabilised in the presence of wildtype eEF1A2. I used CRISPR on LUHMES cells to make a mutant neuronal cell line containing the D252H mutation in eEF1A2. Due to time restraints no phenotypic differences between the wild type line and the D252H mutation line have yet been identified, but would form the focus of a future project.

abstract: Trichloroethene (TCE) is a ubiquitous soil and groundwater contaminant. The most common bioremediation approach for TCE relies on the process of reductive dechlorination by Dehalococcoides mccartyi. D. mccartyi use TCE, dichloroethene, and vinyl chloride as electron acceptors and hydrogen as an electron donor. At contaminated sites, reductive dechlorination is typically promoted by adding a fermentable substrate, which is broken down to short chain fatty acids, simple alcohols, and hydrogen. This study explored microbial chain elongation (MCE), instead of fermentation, to promote TCE reductive dechlorination. In MCE, microbes use simple substrates (e.g., acetate, ethanol) to build medium chain fatty acids and also produce hydrogen during this process. Soil microcosm using TCE and acetate and ethanol as MCE substrates were established under anaerobic conditions. In soil microcosms with synthetic groundwater and natural groundwater, ethene was the main product from TCE reductive dechlorination and butyrate and hydrogen were the main products from MCE. Transfer microcosms using TCE and either acetate and ethanol, ethanol, or acetate were also established. The transfers with TCE and ethanol showed the faster rates of reductive dechlorination and produced more elongated products (i.e., hexanoate). The microbial groups enriched in the soil microcosms likely responsible for chain elongation were most similar to Clostridium genus. These investigations showed the potential for synergistic microbial chain elongation and reductive dechlorination of chlorinated ethenes. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2019

Fatty acids are important regulators in the control of mammalian energy homeostasis. They are ingested in the diet but a significant amount are also endogenously produced by de novo lipogenesis. Fatty acid elongation beyond 16 carbons (palmitic acid) can occur to generate very long chain fatty acids (VLCFA), a process that is initiated by the rate-limiting condensation reaction. To date, six mammalian enzymes responsible for this reaction, ELOVL1-6 (Elongation of very long chain fatty acid), have been characterized. All of them exert substrate specificity and tissue-specific gene expression. In this thesis, factors that regulate fatty acid metabolism and, in particular, fatty acid synthesis and elongation will be presented. The enclosed papers discuss issues as to how Elovl3 is regulated in liver and in different adipose depots and what effects ablation of this enzyme causes to lipid homeostasis. Hepatic Elovl3 gene expression followed a circadian rhythm, present exclusively in sexually mature male mice. In contrast to the expression of several other lipogenic genes, Elovl3 gene expression was not affected by fasting or refeeding. Instead, the gene expression was influenced by steroid hormones such as glucocorticoids and sex hormones. Interestingly, despite reduced levels of leptin, Elovl3-ablated mice were shown to be resistant to diet induced weight gain, which seemed to be due to a decreased ratio between energy intake and energy expenditure. This phenotype was more pronounced in female mice. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript.

Den här rapporten redovisar examensarbetet vars huvudsyfte var att förstå teori och beräkningsgången bakom förspända betongelement samt att jämföra den med teorin för slakarmerade betongelement. Arbetet valdes eftersom inga kurser under studietiden har beaktat denna typ av utformning samt eftersom tillämningen av kunskapen inom området är stor ute i arbetslivet. Arbetet slutfördes genom inläsning av litteratur samt handledning. Det visade sig efter arbetet var slutfört att några delar av teorin och beräkningsgången bakom förspända betongelement var lik den som används vid slakarmerade betongelement, dock existerade även många skillnader. Likheterna erhålls bland annat vid beräkningarna av moment- och tvärkraftskapaciteterna. Skillnaden är att många extra steg måste utföras vid dimensioneringen, steg som till största del bara av olika kontroller, vilka utfördes bland annat vid dimensioneringen av tillverkningsprocessen och i brottgränstillstånd. Slutligen kunde det konstateras att förspända betongelement har många fördelar, vilka bland annat är att större spännvidder, mindre dimensioner på konstruktionerna samt mindre deformationer kan erhållas. Dock så krävs en större mängd beräkningar vid förspända än för slakarmerade betongelement. / The objective of this thesis is to understand the theory and learn the calculation behind prestressed concrete elements and to compare it with the theory of ordinary reinforced concrete elements. This thesis work was chosen in order to promote the study of prestressed concrete and because it´s broad application in civil engineering. The worked was completed by reading literature and guidance. It turned out after the work was completed that some parts of the theory and calculation behind prestressed concrete was similar to that used in the ordinary reinforced concrete. However, there were also many differences that existed. Some of the similarities are obtained when the capacities of moment and shear are calculated. The differences is that many extra steps are required when the design are performed, steps who for the most part due to different controls and are required to be performed to ensure the safety of the design. The controls are to be performed, among other, in the design of the manufacturing process and in the ultimate limit state. Finally, it is found that prestressed concrete elements have many benefits, which includes larger spans, smaller dimensions for structures and that smaller deformations can be obtained. However, it will require a larger amount of calculations as compared to ordinary reinforced concrete.

The development of cottons with improved fiber quality has been a major objective in breeding programs around the world. Breeders have focused their attention on improving fiber strength and length, and have generally not used fiber elongation in the selection process. Although literature has reported a negative correlation between fiber elongation and tenacity, this correlation is weak and should not prevent breeders from simultaneously improving fiber tenacity and fiber elongation. Furthermore, the work of rupture property, important in the spinning process, could be best enhanced by improving both fiber tenacity and fiber elongation. Fifteen populations were developed in 2007 by crossing good quality breeding lines with high elongation measurements to ‘FM 958’; a High Plains standard cultivar with good fiber quality but reduced elongation. Samples in every generation were ginned on a laboratory saw gin, and the lint was tested on HVI (High Volume Instrument). The F2 and F3 generations showed a wide range of variation for elongation (6.9% - 12.8% for the F2 and 4% - 9.20% for the F3) allowing divergent selection for low and high fiber elongation. A correlation (r) of -0.32 between strength and elongation was observed in the F2 individual plant selections. In the F3, the correlation (r) between strength and elongation was -0.36, and in the F4 the correlation (r) was -0.08. Nine lines were selected from the original 15 populations for spinning tests. The correlation between fiber elongation and strength for these lines was positive (r=0.424), indicating that with targeted selection, fiber elongation and strength can be simultaneously improved. Fiber elongation was positively correlated with yarn tensile properties tenacity (r=0.11), work-to-break (r=0.68) and breaking elongation (r=0.87); and was negatively correlated with yarn evenness properties, number of thin places (r=-0.16), number of thick places (r=-0.9), nep count (r=-0.24), hairiness (r=-0.38) and total number of imperfections (r=-0.38). All selections for high elongation were superior for all tensile properties compared to the low selections and the check in the analysis over locations and in each location. Furthermore, selections for high elongation were significantly different from the selections for low elongation and the check. In addition to developing lines for fiber spinning tests with improved, or differentiated, fiber elongation, this project was amended to evaluate and determine the heritability of fiber elongation. Three different methodologies were used to obtain estimates of heritability; variance components, parent off-spring regression, and realized heritability using F3, F4, and F5 generation. No inbreeding was assumed because there was no family structure in the generations within this study. Estimates of heritability by the variance component methods in the F3, F4 and F5 were 69.5%, 56.75% and 47.9% respectively; indicating that 40-50% of the variation was due to non-genetic effects. Parent off-spring regression estimates of heritability were 66.1% for the F3-4 and 62.8% for the F4-5; indicating a high resemblance from parents to off-spring. Estimates of realized heritability were obtained to determine the progress realized from selection for the low and high selection for fiber elongation. Estimates were intermediate (0.44–0.55), indicating moderately good progress from selection. The results from this project demonstrate that it is possible to improve fiber elongation and to break the negative correlation between elongation and strength. Furthermore, it has been demonstrated that improving fiber elongation results in the increase of length uniformity index and decreased short fiber content. Additionally, directed divergent selection was a successful methodology for the improvement of fiber elongation, and was useful to demonstrate that higher fiber elongation has a positive effect on yarn tensile properties, yarn evenness and processing. The development of new cultivars with improved fiber elongation will improve the quality and reputation of U. S.-grown cotton. The ultimate result will be better yarn quality and improved weaving efficiency, and particularly address current weaknesses in U. S. –grown cotton cultivars, especially from the High Plains of Texas, of more short fiber content, lower uniformity ratios, and weaker yarn strength.

In 1975, Elongation Factor P (EF-P) protein was first discovered in the bacterium Escherichia coli. EF-P is believed to facilitate the translation of proteins by stimulating peptide bond synthesis for a number of different aminoacyl-tRNA molecules in conjunction with the 70S ribosome peptidyl transferase. Known eukaryotic homologs, eukaryotic translation initiation factor 5A (eIF-5A) of EF-P exist but with very low sequence conservation. Nevertheless, because of the high sequence similarities seen between bacterial EF-Ps and its low sequence similarity with eIF-5A, there is interest in the pharmaceutical industry of developing a novel antibacterial drug that inhibits EF-P. Of 322 completely sequenced bacterial genomes stored in GenBank, only one organism lacked an EF-P protein. Interestingly, sixty-six genomes were discovered to carry a duplicate copy of efp. The EF-P sequences were then used to construct a protein phylogenetic tree, which provided evidence of horizontal and vertical gene transfer as well as gene duplication. To lend support to these findings, EF-P GC content, codon usage, and nucleotide and amino acid sequences were analyzed with positive and negative controls. The adjacent 10 kb upstream and downstream regions of efp were also retrieved to determine if gene order is conserved in distantly related species. While gene order was not preserved in all species, two interesting trends were seen in some of the distantly related species. The EF-P gene was conserved beside Acetyl-CoA carboxylase genes, accB and accC in certain organisms. In addition, some efp sequences were flanked by two insertion sequence elements. Evidence of gene duplication and horizontal transfers of regions were also observed in the upstream and downstream regions of efp. In combination, phylogenetic, sequence analyses, and gene order conservation confirmed evidence of the complex history of the efp genes, which showed incongruencies relative to the universal phylogenetic tree. To determine how efp is regulated, the upstream regions of efp were used to try to predict motifs in silico. While statistically significant motifs were discovered in the upstream regions of the orthologous efp genes, no conclusive similarities to known binding sites such as the sigma factor binding sites or regulatory protein binding sites were observed. This work may facilitate and enhance the understanding of the regulation, conservation, and role of EF-P in protein translation.

In 1975, Elongation Factor P (EF-P) protein was first discovered in the bacterium Escherichia coli. EF-P is believed to facilitate the translation of proteins by stimulating peptide bond synthesis for a number of different aminoacyl-tRNA molecules in conjunction with the 70S ribosome peptidyl transferase. Known eukaryotic homologs, eukaryotic translation initiation factor 5A (eIF-5A) of EF-P exist but with very low sequence conservation. Nevertheless, because of the high sequence similarities seen between bacterial EF-Ps and its low sequence similarity with eIF-5A, there is interest in the pharmaceutical industry of developing a novel antibacterial drug that inhibits EF-P. Of 322 completely sequenced bacterial genomes stored in GenBank, only one organism lacked an EF-P protein. Interestingly, sixty-six genomes were discovered to carry a duplicate copy of efp. The EF-P sequences were then used to construct a protein phylogenetic tree, which provided evidence of horizontal and vertical gene transfer as well as gene duplication. To lend support to these findings, EF-P GC content, codon usage, and nucleotide and amino acid sequences were analyzed with positive and negative controls. The adjacent 10 kb upstream and downstream regions of efp were also retrieved to determine if gene order is conserved in distantly related species. While gene order was not preserved in all species, two interesting trends were seen in some of the distantly related species. The EF-P gene was conserved beside Acetyl-CoA carboxylase genes, accB and accC in certain organisms. In addition, some efp sequences were flanked by two insertion sequence elements. Evidence of gene duplication and horizontal transfers of regions were also observed in the upstream and downstream regions of efp. In combination, phylogenetic, sequence analyses, and gene order conservation confirmed evidence of the complex history of the efp genes, which showed incongruencies relative to the universal phylogenetic tree. To determine how efp is regulated, the upstream regions of efp were used to try to predict motifs in silico. While statistically significant motifs were discovered in the upstream regions of the orthologous efp genes, no conclusive similarities to known binding sites such as the sigma factor binding sites or regulatory protein binding sites were observed. This work may facilitate and enhance the understanding of the regulation, conservation, and role of EF-P in protein translation.