Pathogen Xylella Fastidiosa
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
16.1 | Regulation of Gene Expression
436 Chapter 16 | Gene Expression 16.1 | Regulation of Gene Expression By the end of this section, you will be able to do the following: • Discuss why every cell does not express all of its genes all of the time • Describe how prokaryotic gene regulation occurs at the transcriptional level • Discuss how eukaryotic gene regulation occurs at the epigenetic, transcriptional, post-transcriptional, translational, and post-translational levels For a cell to function properly, necessary proteins must be synthesized at the proper time and place. All cells control or regulate the synthesis of proteins from information encoded in their DNA. The process of turning on a gene to produce RNA and protein is called gene expression. Whether in a simple unicellular organism or a complex multi-cellular organism, each cell controls when and how its genes are expressed. For this to occur, there must be internal chemical mechanisms that control when a gene is expressed to make RNA and protein, how much of the protein is made, and when it is time to stop making that protein because it is no longer needed. The regulation of gene expression conserves energy and space. It would require a significant amount of energy for an organism to express every gene at all times, so it is more energy efficient to turn on the genes only when they are required. In addition, only expressing a subset of genes in each cell saves space because DNA must be unwound from its tightly coiled structure to transcribe and translate the DNA. Cells would have to be enormous if every protein were expressed in every cell all the time. -
Formation of Heterodimers Between Wild Type and Mutant Trp Aporepressor Polypeptides of Eschem'chia Coli Thomas J
PROTEINS: Structure, Function, and Genetics 4:173-181 (1988) Formation of Heterodimers Between Wild Type and Mutant trp Aporepressor Polypeptides of Eschem'chia coli Thomas J. Graddis,' Lisa S. Klig,' Charles Yanofsky,' and Dale L. Oxender' 'Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109 and 'Department of Biological Sciences, Stanford University, Stanford, California 94305 ABSTRACT Availability of the three-dimen- tophan.1-6 The trp aporepressor is activated by the sional structure of the trp repressor of Escherichia binding of two molecules of its corepressor. Once ac- coli and a large group of repressor mutants has per- tivated, trp repressor binds to the operators of the trp, mitted the identification and analysis of mutants aroH, and trpR operons, regulating transcription ini- with substitutions of the amino acid residues that tiati~n.~,'The aroH and trp operons encode biosyn- form the tryptophan binding pocket. Mutant apore- thetic enzymes, whereas the trpR operon encodes the pressors selected for study were overproduced using trp aporepressor. The trpR gene has been cloned and a multicopy expression plasmid. Equilibrium di- its nucleotide sequence determined.3 The aporepres- alysis with ''C-tryptophan and purified mutant and sor and repressor have been purified and the crystal wild type aporepressors was employed to determine structures of both have been solved at high resolu- tryptophan binding constants. The results obtained ti~n.~-"The trp aporepressor is a dimer of identical indicate that replacement of threonine 44 by methi- 107 residue polypeptides." The existence of the three- onine (TM44) or arginine 84 by histidine (RH84) low- dimensional structures, and the availability of many ers the affinity for tryptophan approximately two- repressor mutants,2i12has facilitated this analysis of and four-fold, respectively. -
Polyamine Biosynthesis in Human Fetal Liver and Brain
Pediat. Res. 8: 231-237 (1974) S-Adenosylmethionine decarboxylase polyamines developmental biochemistry putrescine fetus spermidine ornithine decarboxylase Polyamine Biosynthesis in Human Fetal Liver and Brain JOHN A. STURMAN'~~]AND GERALD E. GAULL Department of Pediatric Research, Institute for Basic liesearch in Mental Retardation, Staten Island, and Department of Pediatrics, Division of Medical Genetics and Clinical Genetics Center, Mount Sinai School of Medicine of the City University of New York, New York, New York, USA Extract S-Adenosylmethionine decarboxylase specific activity in fetal (9.0-25.0 cm crown- rump length) human liver was 20-fold greater than in mature human liver, both in the absence of putrescine (63.1 f 7.2 versus 3.5 =t 0.8 pmol C02/mgprotein/30 min) or in the presence of putrescine (1 16.9 + 8.2 uersus 6.2 =I= 1.0 pmol C02/mg protein/30 min). Extracts of fetal human brain did not have a significantly greater specific ac- tivity of S-adenosylmethionine decarboxylase than extracts of mature human brain when assayed in the absence of putrescine and had less when assayed in the presence of putrescine (84.7 =t 14.9 versus 175.5 f 30.6 pmol C02/mgprotein/30 min). Ornithine decarboxylase specific activity was greater in fetal liver than in mature liver (8.8 =t1.6 versus 1.1 f 0.3 pmol CO 2/mg protein/30 min) and 20-fold greater in fetal brain than in mature brain (7 1.2 =t 12.1 uersus 3.1 =I= 1.4 pmol CO z/mg protein/30 min). -
(12) Patent Application Publication (10) Pub. No.: US 2009/0292100 A1 Fiene Et Al
US 20090292100A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2009/0292100 A1 Fiene et al. (43) Pub. Date: Nov. 26, 2009 (54) PROCESS FOR PREPARING (86). PCT No.: PCT/EP07/57646 PENTAMETHYLENE 1.5-DIISOCYANATE S371 (c)(1), (75) Inventors: Martin Fiene, Niederkirchen (DE): (2), (4) Date: Jan. 9, 2009 (DE);Eckhard Wolfgang Stroefer, Siegel, Mannheim (30) Foreign ApplicationO O Priority Data Limburgerhof (DE); Stephan Aug. 1, 2006 (EP) .................................. O61182.56.4 Freyer, Neustadt (DE); Oskar Zelder, Speyer (DE); Gerhard Publication Classification Schulz, Bad Duerkheim (DE) (51) Int. Cl. Correspondence Address: CSG 18/00 (2006.01) OBLON, SPIVAK, MCCLELLAND MAIER & CD7C 263/2 (2006.01) NEUSTADT, L.L.P. CI2P I3/00 (2006.01) 194O DUKE STREET CD7C 263/10 (2006.01) ALEXANDRIA, VA 22314 (US) (52) U.S. Cl. ........... 528/85; 560/348; 435/128; 560/347; 560/355 (73) Assignee: BASFSE, LUDWIGSHAFEN (DE) (57) ABSTRACT (21) Appl. No.: 12/373,088 The present invention relates to a process for preparing pen tamethylene 1,5-diisocyanate, to pentamethylene 1,5-diiso (22) PCT Filed: Jul. 25, 2007 cyanate prepared in this way and to the use thereof. US 2009/0292100 A1 Nov. 26, 2009 PROCESS FOR PREPARING ene diisocyanates, especially pentamethylene 1,4-diisocyan PENTAMETHYLENE 1.5-DIISOCYANATE ate. Depending on its preparation, this proportion may be up to several % by weight. 0014. The pentamethylene 1,5-diisocyanate prepared in 0001. The present invention relates to a process for pre accordance with the invention has, in contrast, a proportion of paring pentamethylene 1,5-diisocyanate, to pentamethylene the branched pentamethylene diisocyanate isomers of in each 1.5-diisocyanate prepared in this way and to the use thereof. -
Discovery and Characterization of Blse, a Radical S- Adenosyl-L-Methionine Decarboxylase Involved in the Blasticidin S Biosynthetic Pathway
Discovery and Characterization of BlsE, a Radical S- Adenosyl-L-methionine Decarboxylase Involved in the Blasticidin S Biosynthetic Pathway Jun Feng1, Jun Wu1, Nan Dai2, Shuangjun Lin1, H. Howard Xu3, Zixin Deng1, Xinyi He1* 1 State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China, 2 New England Biolabs, Inc., Research Department, Ipswich, Massachusetts, United States of America, 3 Department of Biological Sciences, California State University Los Angeles, Los Angeles, California, United States of America Abstract BlsE, a predicted radical S-adenosyl-L-methionine (SAM) protein, was anaerobically purified and reconstituted in vitro to study its function in the blasticidin S biosynthetic pathway. The putative role of BlsE was elucidated based on bioinformatics analysis, genetic inactivation and biochemical characterization. Biochemical results showed that BlsE is a SAM-dependent radical enzyme that utilizes cytosylglucuronic acid, the accumulated intermediate metabolite in blsE mutant, as substrate and catalyzes decarboxylation at the C5 position of the glucoside residue to yield cytosylarabinopyranose. Additionally, we report the purification and reconstitution of BlsE, characterization of its [4Fe–4S] cluster using UV-vis and electron paramagnetic resonance (EPR) spectroscopic analysis, and investigation of the ability of flavodoxin (Fld), flavodoxin 2+ reductase (Fpr) and NADPH to reduce the [4Fe–4S] cluster. Mutagenesis studies demonstrated that Cys31, Cys35, Cys38 in the C666C6MC motif and Gly73, Gly74, Glu75, Pro76 in the GGEP motif were crucial amino acids for BlsE activity while mutation of Met37 had little effect on its function. Our results indicate that BlsE represents a typical [4Fe–4S]-containing radical SAM enzyme and it catalyzes decarboxylation in blasticidin S biosynthesis. -
Application of Models for Biomolecular Structure and Interactions to Understand and Influence Biological Function
Application of Models for Biomolecular Structure and Interactions to Understand and Influence Biological Function Zur Erlangung des akademischen Grades eines DOKTORS DER NATURWISSENSCHAFTEN (Dr. rer. nat.) Fakultät für Chemie und Biowissenschaften Karlsruher Institut für Technologie (KIT) - Universitätsbereich genehmigte DISSERTATION von Irene Meliciani aus Rom (Italien) Dekan: Prof. Dr. Martin Bastmeyer Referent: Prof. Dr. Stefan Bräse Korreferent: Apl. Prof. Dr. Wolfgang Wenzel Tag der mündlichen Prüfung: 19.10.2011 a mamma e papà Application of Models for Biomolecular Structure and Interactions to Understand and Influence Biological Function Irene Meliciani Karlsruher Institut für Technologie Institut für Nanotechnologie Intitut für Organische Chemie Zusammenfassung Die Forschung in den Lebenswissenschaften hat in den letzten Jahrzehnten zu einem enormen Wissensgewinns bezüglich der Abläufe zellulärer Prozesse und ihrer Steuerung geführt. Die Steuerung biologischer Prozesse wird vielfach über Kontaktwechselwirkungen der daran beteiligten Biomoleküle bewältigt. Mit dieser Arbeit möchte ich zu einem besseren Verständnis biomolekularer Interaktionen beitragen. Ein Teil dieser Arbeit beschäftigt sich mit der Untersuchung von Proteininteraktionen, wobei als Methoden für die Modellierung von Protein-Protein-Wechselwirkungen (POEM) und für die Protein-Liganden-Wechselwirkung (FLEXSCREEN) eingesetzt wurden. Es wurden die Interaktionen der Chemokinrezeptoren CCR3 und CXCR1 mit für den Entzündungsverlauf wichtigen Steuerungsmolekülen (Chemokinen) -
Teaching Gene Regulation in the High School Classroom, AP Biology, Stefanie H
Wofford College Digital Commons @ Wofford Arthur Vining Davis High Impact Fellows Projects High Impact Curriculum Fellows 4-30-2014 Teaching Gene Regulation in the High School Classroom, AP Biology, Stefanie H. Baker Wofford College, [email protected] Marie Fox Broome High School Leigh Smith Wofford College Follow this and additional works at: http://digitalcommons.wofford.edu/avdproject Part of the Biology Commons, and the Genetics Commons Recommended Citation Baker, Stefanie H.; Fox, Marie; and Smith, Leigh, "Teaching Gene Regulation in the High School Classroom, AP Biology," (2014). Arthur Vining Davis High Impact Fellows Projects. Paper 22. http://digitalcommons.wofford.edu/avdproject/22 This Article is brought to you for free and open access by the High Impact Curriculum Fellows at Digital Commons @ Wofford. It has been accepted for inclusion in Arthur Vining Davis High Impact Fellows Projects by an authorized administrator of Digital Commons @ Wofford. For more information, please contact [email protected]. High Impact Fellows Project Overview Project Title, Course Name, Grade Level Teaching Gene Regulation in the High School Classroom, AP Biology, Grades 9-12 Team Members Student: Leigh Smith High School Teacher: Marie Fox School: Broome High School Wofford Faculty: Dr. Stefanie Baker Department: Biology Brief Description of Project This project sought to enhance high school students’ understanding of gene regulation as taught in an Advanced Placement Biology course. We accomplished this by designing and implementing a lab module that included a pre-lab assessment, a hands-on classroom experiment, and a post-lab assessment in the form of a lab poster. Students developed lab skills while simultaneously learning about course content. -
Mutant Tryptophan Aporepressors with Altered Specificities Of
Copyright 0 1991 by the Genetics Society of America Mutant Tryptophan Aporepressors With Altered Specificitiesof Corepressor Recognition Dennis N. Arvidson,' Michael Shapiro' and Philip Youderian' Department of Biological Sciences, University of Southern Calqornia, Los Angeles, Calqornia 90089 Manuscript received November 20, 1990 Accepted for publication January 19, 199 1 ABSTRACT The Escherichia coli trpR gene encodes tryptophan aporepressor, which binds the corepressor ligand, L-tryptophan, to form an active repressor complex. The side chain of residue valine 58 of Trp aporepressor sits at the bottom of the corepressor @-tryptophan) binding pocket. Mutant trpR genes encoding changes of Vals8 to the other 19 naturally occurring amino acids were made. Each of the mutant proteins requires a higher intracellular concentration of tryptophan for activation of DNA binding than wild-type aporepressor. Whereas wild-type aporepressor is activated better by 5- methyltryptophan (5-MT) than by tryptophan, IlesHand other mutant aporepressors prefer tryptophan to 5-MT as corepressor, and Ala5' and GIY'~prefer 5-MT much more strongly than wild-type aporepressor in vivo. These mutant aporepressors are the first examples of DNA-binding proteins with altered specificities ofcofactor recognition. ANY regulatory proteins areallosteric, and bind intermonomer interactions stabilize its extraordinary M small metabolic intermediates that modify their hydrophobic core. The aporepressor dimer denatures activities, allowing the intracellular pattern of gene at a very high temperature (>go") (BAEet al. 1988). expression to respond to physiologicalchange. For Comparisons of the crystal structures of repressor example, the Escherichia coli tryptophan aporepressor (SCHEVITZet al. 1985; LAWSONet al. 1988;OTWI- (TrpR) protein binds DNA poorly. However, when NOWSKI et al. -
Phytohormones Regulate Accumulation of Osmolytes Under Abiotic Stress
biomolecules Review Phytohormones Regulate Accumulation of Osmolytes Under Abiotic Stress Anket Sharma 1,* , Babar Shahzad 2, Vinod Kumar 3 , Sukhmeen Kaur Kohli 4, Gagan Preet Singh Sidhu 5, Aditi Shreeya Bali 6, Neha Handa 7 , Dhriti Kapoor 7, Renu Bhardwaj 4 and Bingsong Zheng 1,* 1 State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China 2 School of Land and Food, University of Tasmania, Hobart, Tasmania 7005, Australia 3 Department of Botany, DAV University, Sarmastpur, Jalandhar 144012, Punjab, India 4 Plant Stress Physiology Laboratory, Department of Botanical & Environmental Sciences, Guru Nanak Dev University, Amritsar 143005, India 5 Department of Environment Education, Government College of Commerce and Business Administration, Chandigarh 160047, India 6 Mehr Chand Mahajan D.A.V. College for Women, Chandigarh 160036, India 7 School of Bioengineering & Biosciences, Lovely Professional University, Phagwara 144411, India * Correspondence: [email protected] (A.S.); [email protected] (B.Z.); Tel.: +86-(0)-5716-373-0936 (B.Z.) Received: 13 June 2019; Accepted: 16 July 2019; Published: 17 July 2019 Abstract: Plants face a variety of abiotic stresses, which generate reactive oxygen species (ROS), and ultimately obstruct normal growth and development of plants. To prevent cellular damage caused by oxidative stress, plants accumulate certain compatible solutes known as osmolytes to safeguard the cellular machinery. The most common osmolytes that play crucial role in osmoregulation are proline, glycine-betaine, polyamines, and sugars. These compounds stabilize the osmotic differences between surroundings of cell and the cytosol. Besides, they also protect the plant cells from oxidative stress by inhibiting the production of harmful ROS like hydroxyl ions, superoxide ions, hydrogen peroxide, and other free radicals. -
Development of Novel Transgenic Zebrafish
DEVELOPMENT OF NOVEL TRANSGENIC ZEBRAFISH MODELS AND THEIR APPLICATION TO STUDIES ON ENVIRONMENTAL OESTROGENS Submitted by Jon Marc Green to the University of Exeter as a thesis for the degree of Doctor of Philosophy in Biological Sciences, September 2016 This thesis is available for Library use on the understanding that it is copyright material and that no quotation from the thesis may be published without proper acknowledgement. I certify that all material in this thesis which is not my own work has been identified and that no material has previously been submitted and approved for the award of a degree by this or any other University. (Signature) ……………………………………………(Jon Marc Green) 1 Abstract Oestrogenic chemicals have become increasingly associated with health effects in wildlife populations and humans. Transgenic animal models have been developed to understand the mechanisms by which these oestrogenic chemicals alter hormonal signalling pathways and how these alterations can lead to chronic health effects. The use of highly informative transgenic animal models will also result in better use and potential reduction of intact animals used in animal testing in line with the principles of the 3Rs. In this thesis work, two novel oestrogen responsive transgenic zebrafish models have been generated to investigate the effects of oestrogenic chemicals, identify their tissue targets and better understand the temporal dynamics of these responses. Both models express the pigment-free ‘Casper’ (a mutant line lacking skin pigment) phenotype, which facilitate identification of responding target tissues in the whole fish in all fish life stages (embryos to adults). The oestrogen response element green fluorescent (ERE-GFP)-Casper model was generated by crossing an established ERE-GFP line with the skin pigment free Casper line. -
Binds Multiple Sites Within the Aroh and Trp Operators
Downloaded from genesdev.cshlp.org on September 30, 2021 - Published by Cold Spring Harbor Laboratory Press Escherichia cod tryptophan repressor binds multiple sites within the aroH and trp operators Andrew A. Kumamoto, ~ William G. Miller, 2 and Robert P. GunsalusL2 1Molecular Biology Institute and the 2Department of Microbiology, University of Califomia, Los Angeles, Califomia 90024 USA DNase I footprinting and methylation protection studies have been used to analyze the binding of Escherichia coli Trp repressor to the trpR, aroH, and trp operators. The methylation protection assay shows that Trp repressor binds in two successive major grooves of the trpR operator, three successive major grooves of the aroH operator, and four successive major grooves of the trp operator. The simplest model that explains the difference in Trp repressor interaction at the three operators is that the aroH and trp operators are composed of multiple, helically stacked binding sites. When viewed in three dimensions, each site is positioned on a different face of the DNA, and together process up the surface of the DNA helix. Analysis of a deletion derivative of the trp operator supports this model. [Key Words" Trp repressor; aroH operator; trp operator; repressor binding] Received February 23, 1987; revised version accepted June 6, 1987. The Trp repressor of Escherichia coli coordinately regu- and by the isolation of constitutive mutations within lates the expression of the trp, aroH, and trpR operons in the trp operator {Bennett and Yanofsky 1978). These op- response to the intracellular levels of L-tryptophan erator constitutive mutations map at positions -16, (Cohen and Jacob 1959; Brown 1968; Rose et al. -
The Tryptophan Biosynthetic Pathway Trp Biosynthesis Is a Biologically Expensive, Complicated Process
E. Coli Trp repressor The tryptophan repressor proteins The trp repressor proteins regulate transcription of several diferent operons located at separate sites on the E. coli chromosome. In addition to the trp operon, this repressor represses transcription of aroH, a single-gene operon that encodes an enzyme required for the synthesis of all aromatic amino acids, and trpR, another single-gene operon encoding the trp repressor itself. Such coordinately regulated operons constitute a regulon. Although all three operons in this regulon are repressed by the trp repressor, the extent of repression varies from about twofold for the aroH operon to seventyfold for the trp operon. This variation results from diferences in the afnity of trp repressor for the specific operator in each of these operons, diferences in the position of the operators relative to the −10 and −35 sequences of each promoter, and diferences in the strengths of the three promoters. Thus the specific nucleotide sequences of the promoters and operators in a regulon allow the same repressor to diferentially regulate transcription of the component operons. The tryptophan biosynthetic pathway Trp biosynthesis is a biologically expensive, complicated process. In fact, the products of four other pathways are essential contributors of carbon or nitrogen during tryptophan formation. Thus, the principal pathway precursor, chorismate, is also the precursor of the other aromatic amino acids, phenylalanine and tyrosine, as well as serving as the precursor of p- aminobenzoic acid and several other metabolites. In addition, glutamine, phosphoribosylpyrophosphate, and L-serine contribute nitrogen and/or carbon during tryptophan formation. FIGURE 1. The genes, enzymes, and reactions of the tryptophan biosynthetic pathway.