Identification and Characterization of Zn(II)-responsive Genes and Proteins in E. Coli

Identification and Characterization of Zn(II)-responsive Genes and Proteins in E. Coli PDF Author: James Allen Easton
Publisher:
ISBN:
Category : Escherichia coli
Languages : en
Pages : 168

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Book Description
Transition metal ion homeostasis is absolutely crucial for the survival of all organisms. Zinc (Zn(II)) is perhaps one of the most important, yet least studied transition metals. Previous studies indicate that intracellular Zn(II) levels in E. coli are in the low millimolar range, yet there is less than one "free" Zn(II) ion per cell. All of the intracellular Zn(II) must then be bound and Zn(II) must be delivered from transporters and inserted into Zn(II)-metalloproteins. The cytoplasmic transport of transition metals, such as copper, iron, nickel, manganese, and arsenic, is accomplished by a group of proteins called metallochaperones. No such metallochaperone has been identified for Zn(II). In an effort to identify the Zn(II) metallochaperones in E. coli, proteomic and genomic studies were conducted. Proteomic studies were used to probe for the time-dependent response of E. coli to stress by Zn(II) excess. Genomic studies were used to probe for the transcriptional response of E. coli to stress by Zn(II) excess and deficiency. Several Zn(II)-metallochaperone candidates were identified, and these proteins were cloned, over-expressed, purified, and characterized. Trigger factor was found to be down-regulated at the proteomic level in response to excess Zn(II). Over-expression and characterization of trigger factor show that it tightly binds 0.5 Zn(II)/monomer; however, spectroscopic studies showed that Zn(II) binding is most likely adventitious. GatY/GatZ Zn(II)-responsive proteins that are part of the galactitol catabolic pathway. GatY was over-expressed and shown to bind 2 Zn(II) equivalents per enzyme. GatZ, reported to be necessary for GatY function, was tested for Zn(II)-binding and shown to not bind Zn(II). A transcript found to be highly up-regulated was ykgM. We cloned and over-expressed YkgM to elucidate why it is highly responsive to Zn(II). We determined that YkgM does not bind Zn(II), and may substitute for Zn(II)-containing ribosomal protein L31 in Zn(II)-limiting conditions. ZnuA was cloned, over-expressed, purified, and characterized. We found that ZnuA tightly binds 2 equivalents of Zn(II) per monomer. Our proteomic and genomic data suggest that there are no soluble, cytoplasmic Zn(II) metallochaperones in E. coli. Based on this conclusion, a novel model is hypothesized that explains Zn(II) transport in E. coli cytoplasm.

Identification and Characterization of Zn(II)-responsive Genes and Proteins in E. Coli

Identification and Characterization of Zn(II)-responsive Genes and Proteins in E. Coli PDF Author: James Allen Easton
Publisher:
ISBN:
Category : Escherichia coli
Languages : en
Pages : 168

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Book Description
Transition metal ion homeostasis is absolutely crucial for the survival of all organisms. Zinc (Zn(II)) is perhaps one of the most important, yet least studied transition metals. Previous studies indicate that intracellular Zn(II) levels in E. coli are in the low millimolar range, yet there is less than one "free" Zn(II) ion per cell. All of the intracellular Zn(II) must then be bound and Zn(II) must be delivered from transporters and inserted into Zn(II)-metalloproteins. The cytoplasmic transport of transition metals, such as copper, iron, nickel, manganese, and arsenic, is accomplished by a group of proteins called metallochaperones. No such metallochaperone has been identified for Zn(II). In an effort to identify the Zn(II) metallochaperones in E. coli, proteomic and genomic studies were conducted. Proteomic studies were used to probe for the time-dependent response of E. coli to stress by Zn(II) excess. Genomic studies were used to probe for the transcriptional response of E. coli to stress by Zn(II) excess and deficiency. Several Zn(II)-metallochaperone candidates were identified, and these proteins were cloned, over-expressed, purified, and characterized. Trigger factor was found to be down-regulated at the proteomic level in response to excess Zn(II). Over-expression and characterization of trigger factor show that it tightly binds 0.5 Zn(II)/monomer; however, spectroscopic studies showed that Zn(II) binding is most likely adventitious. GatY/GatZ Zn(II)-responsive proteins that are part of the galactitol catabolic pathway. GatY was over-expressed and shown to bind 2 Zn(II) equivalents per enzyme. GatZ, reported to be necessary for GatY function, was tested for Zn(II)-binding and shown to not bind Zn(II). A transcript found to be highly up-regulated was ykgM. We cloned and over-expressed YkgM to elucidate why it is highly responsive to Zn(II). We determined that YkgM does not bind Zn(II), and may substitute for Zn(II)-containing ribosomal protein L31 in Zn(II)-limiting conditions. ZnuA was cloned, over-expressed, purified, and characterized. We found that ZnuA tightly binds 2 equivalents of Zn(II) per monomer. Our proteomic and genomic data suggest that there are no soluble, cytoplasmic Zn(II) metallochaperones in E. coli. Based on this conclusion, a novel model is hypothesized that explains Zn(II) transport in E. coli cytoplasm.

Zinc Biochemistry, Physiology, and Homeostasis

Zinc Biochemistry, Physiology, and Homeostasis PDF Author: W. Maret
Publisher: Springer Science & Business Media
ISBN: 9401737282
Category : Science
Languages : en
Pages : 232

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Book Description
Chapters in this book review the remarkable advances in the field of zinc biology over the last decade. Zinc is essential for life, in particular for growth and development, through its role in hundreds of zinc enzymes and thousands of zinc proteins. Its catalytic, structural, and regulatory functions in these proteins impact metabolism, gene expression, and signal transduction, including neurotransmission. Among the micronutrients, zinc may rank with iron as to its importance for public health. The topics covered range from single molecules to cells and to whole organisms: the chemistry, design, and application of fluorophores for the determination of cellular zinc; the role of zinc in proliferation, differentiation, and apoptosis of cells; proteins that transport, sense, and distribute zinc and together form a cellular homeostatic system; the coordination chemistry of zinc in metalloproteins; the role of zinc in the brain as a neuromodulator/transmitter; the dependence of the immune system on zinc; zinc homeostasis in the whole human body.

Cumulated Index Medicus

Cumulated Index Medicus PDF Author:
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 1844

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Book Description


Metal Transporters

Metal Transporters PDF Author: Jose M. Arguello
Publisher: Academic Press
ISBN: 0123943906
Category : Science
Languages : en
Pages : 478

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Book Description
This volume of Current Topics in Membranes focuses on metal transmembrane transporters and pumps, a recently discovered family of membrane proteins with many important roles in the physiology of living organisms. The book summarizes the most recent advances in the field of metal ion transport and provides a broad overview of the major classes of transporters involved in homeostasis of heavy metals. Various families of the transporters and metal specificities are discussed with the focus on the structural and mechanistic aspects of their function and regulation. The reader will access information obtained through a variety of approaches ranging from X-ray crystallography to cell biology and bioinformatics, which have been applied to transporters identified in diverse biological systems, such as pathogenic bacteria, plants, humans and others. Field is cutting-edge and a lot of the information is new to research community Wide breadth of topic coverage Contributors of high renown and expertise

Antimicrobial Resistance in Bacteria from Livestock and Companion Animals

Antimicrobial Resistance in Bacteria from Livestock and Companion Animals PDF Author: Stefan Schwarz
Publisher: John Wiley & Sons
ISBN: 155581980X
Category : Medical
Languages : en
Pages : 400

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Book Description
The global spread of antimicrobial-resistant pathogenic bacteria is a continuing challenge to the health care of humans and domesticated animals. With no new agents on the horizon, it is imperative to use antimicrobial agents wisely to preserve their future efficacy. Led by Editors Stefan Schwarz, Lina Maria Cavaco, and Jianzhong Shen with Frank Møller Aarestrup, an international team of experts in antimicrobial resistance of livestock and companion animals has created this valuable reference for veterinary students and practitioners as well as researchers and decision makers interested in understanding and preventing antimicrobial resistance.

Advances in Proteobacteria Research and Application: 2013 Edition

Advances in Proteobacteria Research and Application: 2013 Edition PDF Author:
Publisher: ScholarlyEditions
ISBN: 1481683845
Category : Medical
Languages : en
Pages : 202

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Book Description
Advances in Proteobacteria Research and Application: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Alphaproteobacteria. The editors have built Advances in Proteobacteria Research and Application: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Alphaproteobacteria in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Advances in Proteobacteria Research and Application: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Experiments with Gene Fusions

Experiments with Gene Fusions PDF Author: Thomas J. Silhavy
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 332

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Book Description


Index Medicus

Index Medicus PDF Author:
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 1810

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Book Description
Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.

Stress Response in Pathogenic Bacteria

Stress Response in Pathogenic Bacteria PDF Author: Stephen P. Kidd
Publisher: CABI
ISBN: 1845937600
Category : Science
Languages : en
Pages : 316

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Book Description
The ability of pathogenic bacteria to adapt to various chemical, biochemical and physical conditions within the human host and their ability to respond to stresses generated in these environments is a central feature of infectious diseases and the outcome of bacterial infection. This book covers the key aspects of this rapidly developing field, including the generation of stresses by the host immune system, bacterial response to reactive chemicals, and adaptation to environmental conditions of anatomical niches such as the gut, mouth and urogenital tract. It also addresses the increasing importance of different metal ions in the pathogenesis and survival of specific bacteria. With chapters by active research experts in the field, the book provides a comprehensive outline of the current understanding of this field, the latest developments and where future research is likely to be directed.

Metals in Cells

Metals in Cells PDF Author: Valeria Culotta
Publisher: John Wiley & Sons
ISBN: 1118636864
Category : Science
Languages : en
Pages : 608

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Book Description
Over the last three decades a lot of research on the role of metals in biochemistry and medicine has been done. As a result many structures of biomolecules with metals have been characterized and medicinal chemistry studied the effects of metal containing drugs. This new book (from the EIBC Book Series) covers recent advances made by top researchers in the field of metals in cells [the “metallome”] and include: regulated metal ion uptake and trafficking, sensing of metals within cells and across tissues, and identification of the vast cellular factors designed to orchestrate assembly of metal cofactor sites while minimizing toxic side reactions of metals. In addition, it features aspects of metals in disease, including the role of metals in neuro-degeneration, liver disease, and inflammation, as a way to highlight the detrimental effects of mishandling of metal trafficking and response to "foreign" metals. With the breadth of our recently acquired understanding of metals in cells, a book that features key aspects of cellular handling of inorganic elements is both timely and important. At this point in our understanding, it is worthwhile to step back and take an expansive view of how far our understanding has come, while also highlighting how much we still do not know. The content from this book will publish online, as part of EIBC in December 2013, find out more about the Encyclopedia of Inorganic and Bioinorganic Chemistry, the essential online resource for researchers and students working in all areas of inorganic and bioinorganic chemistry.