Author: Hee-Jeon Hong
Publisher: Humana
ISBN: 9781493981144
Category : Science
Languages : en
Pages : 288
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Book Description
This volume brings together the most widely used and important protocols currently being employed in researching and understanding bacterial cell wall homeostasis. Chapters in Bacterial Cell Wall Homeostasis cover a variety of subjects, such as: modern microscopy techniques and other biophysical methods used to characterize the subcellular structure of the bacterial cell wall; high-throughput approaches that can be used to identify all the genes and proteins that participate in the correct functioning of an organism’s cell wall; protocols for assaying individual gene products for specific cell wall functions or identify chemicals with inhibitory activity against the cell wall; and methods for analyzing the non-protein components of the cell wall and the increasing use of computational approaches for predicting and modeling cell wall related functions and processes. Written in the highly successful Methods in Molecular Biology series format, chapters include introduction to their respective topics, lists of the necessary material and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Thorough and cutting-edge, Bacterial Cell Wall Homeostasis: Methods and Protocols emphasizes the diversity of the research taking place in bacterial cell wall homeostasis, and explains how the integration of information from across multiple disciplines is going to be essential if a holistic understanding of this important process is to be obtained.
Author: Anna Isabell Weaver
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
The bacterial cell wall comprises a strong, covalently closed network of peptidoglycan (PG) strands. While PG synthesis is generally essential for bacterial survival, the cell wall is also by necessity a dynamic structure and undergoes constant degradation and remodeling by "autolysins," enzymes that break bonds within PG. One class of autolysin, the lytic transglycosylases (LTGs), cleaves the glycosidic linkages within PG strands. Despite LTGs having well-described biochemical properties, LTG redundancy and diversity have stymied understanding of their fundamental physiological roles. LTGs have been mostly assigned various non-essential, or poorly defined, pleiotropic functions and so there has been no clear evidence to explain why this extreme redundancy, usually indicating an essential function, is so widely conserved amongst diverse bacteria. The diarrheal pathogen Vibrio cholerae encodes eight known LTGs and inactivating single LTGs rarely generates a significant mutant phenotype from which to infer physiological importance. Therefore, rather than directly pursuing individual LTGs, we sought to explore the collective function of the entire enzymatic class by interrogating a mutant lacking all known LTGs. In doing so, we found that V. cholerae must retain at least one active LTG for survival and subsequently characterized the first truly essential role fulfilled by LTGs : clearance of PG debris from the periplasm which accumulates during normal cell wall expansion and remodeling, or during cell wall damage. Coincidentally, this addresses a fundamental question about how bacteria maintain the integrity of a dynamic cell wall through temporal separation of this LTG-mediated autolysis from synthesis, likely independent of previously hypothesized protein-protein interactions. By systematically re-introducing LTGs back into LTG-deficient mutants, we have also created a platform for empirically organizing diverse LTGs into functional families where previously they could only be categorized by their biochemistry. For example, one functional group includes LTGs that are specifically required for clearance of PG debris during septation and daughter cell separation. Another group likely contributes to the elusive, and now confirmed essential, function of releasing newly synthesized PG from the inner membrane. This platform is far from exhaustion and will continue to yield critical information about lytic transglycosylases and their relationship with cell wall homeostasis.
Author: J.-M. Ghuysen
Publisher: Elsevier
ISBN: 0080860877
Category : Science
Languages : en
Pages : 607
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Book Description
Studies of the bacterial cell wall emerged as a new field of research in the early 1950s, and has flourished in a multitude of directions. This excellent book provides an integrated collection of contributions forming a fundamental reference for researchers and of general use to teachers, advanced students in the life sciences, and all scientists in bacterial cell wall research. Chapters include topics such as: Peptidoglycan, an essential constituent of bacterial endospores; Teichoic and teichuronic acids, lipoteichoic acids, lipoglycans, neural complex polysaccharides and several specialized proteins are frequently unique wall-associated components of Gram-positive bacteria; Bacterial cells evolving signal transduction pathways; Underlying mechanisms of bacterial resistance to antibiotics.
Author: Roger Whittenbury
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 304
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Book Description
Being small and compartmentalized, most micro-organisms do not have the advantage that many large multicellular organisms possess. Consequently, a whole range of rapidly acting mechanisms have evolved in them. This symposium covered those mechanisms. The 44th FEMS Symposium covered the major environmental streses and the major compensating homeostatic mechanisms, highlighting the parallel strategies that have evolved, as well as the contrasting ones. The Symposium also considered practically useful means for utilising, or interfering with, homeostasis (e.g. use of antibiotics and some organic acid food preservatives to collapse homeostatic chemiosmotic gradiets and inhibition of repair.
Author: Christine Harper
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Biomechanics and mechanobiology have long been recognized as essential for the growth and function of biological systems, and recent work has demonstrated the importance of mechanical forces for key physiological mechanisms in bacteria. Although the bacterial cell envelope is the primary load-bearing structure of bacteria, the influence of mechanical stress on the bacterial cell envelope and its components is largely understudied. In this thesis I examine the role of mechanical stress on two systems in the bacterial cell envelope: multicomponent efflux complex MacAB-TolC which contributes to antibiotic resistance in Escherichia coli and two-component signaling system VxrAB which controls gene expression for cell wall synthesis in Vibrio cholerae.Multicomponent efflux complexes form a channel through the bacterial cell envelope in order to pump toxins and antibiotics out of the cell. We have previously shown that mechanical stress compromises the assembly and functionality of efflux complex CusCBA; however, it is unknown if other efflux complexes are similarly vulnerable to mechanical stress and the role cell envelope stiffness plays. We expand upon previous work by investigating the influence of mechanical stress on efflux complex MacAB-TolC with and without alterations to cell envelope stiffness. We submitted individual live bacterial cells to controlled mechanical loading using a custom microfluidic device and used single-molecule tracking to observe efflux pump behavior. We found that octahedral shear stress in the cell envelope promotes efflux complex disassembly, suggesting impaired antibiotic resistance capability. Cell envelope stiffness plays a significant role in mediating the effect of mechanical manipulation through the magnitude of octahedral shear stress as well as changes in cell surface area. Our findings demonstrate the importance of mechanical stress in the cell envelope as well as cell envelope stiffness for trans-envelope protein function. Although the bacterial cell envelope is the load-bearing component of the cell, it is unknown if cell envelope homeostasis is responsive to mechanical stress. VxrAB is a two component signaling system with a sensor embedded in the cell envelope and a response receptor that controls gene expression of cell wall synthesis. We submitted cells to mechanical loading using our microfluidic device, hydrostatic pressure, and compression and measured the activity of the VxrAB signaling system in response. We found that cells experiencing greater magnitudes of mechanical load exhibited greater VxrAB signaling. Our results suggest the importance of mechanical signals in cell envelope homeostasis through VxrAB mediated cell wall synthesis. Together, this work suggests the importance of mechanical stress for the function of proteins in the bacterial cell envelope. This work establishes a foundation for future bacterial mechanobiology research and has the potential to advance synthetic biology as well as inform future antibiotic treatment strategies.
Author: Vaidehi Bhupendrakumar Patel
Publisher:
ISBN:
Category :
Languages : en
Pages : 312
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Book Description
Author: Jan Löwe
Publisher: Springer
ISBN: 331953047X
Category : Science
Languages : en
Pages : 457
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Book Description
This book describes the structures and functions of active protein filaments, found in bacteria and archaea, and now known to perform crucial roles in cell division and intra-cellular motility, as well as being essential for controlling cell shape and growth. These roles are possible because the cytoskeletal and cytomotive filaments provide long range order from small subunits. Studies of these filaments are therefore of central importance to understanding prokaryotic cell biology. The wide variation in subunit and polymer structure and its relationship with the range of functions also provide important insights into cell evolution, including the emergence of eukaryotic cells. Individual chapters, written by leading researchers, review the great advances made in the past 20-25 years, and still ongoing, to discover the architectures, dynamics and roles of filaments found in relevant model organisms. Others describe one of the families of dynamic filaments found in many species. The most common types of filament are deeply related to eukaryotic cytoskeletal proteins, notably actin and tubulin that polymerise and depolymerise under the control of nucleotide hydrolysis. Related systems are found to perform a variety of roles, depending on the organisms. Surprisingly, prokaryotes all lack the molecular motors associated with eukaryotic F-actin and microtubules. Archaea, but not bacteria, also have active filaments related to the eukaryotic ESCRT system. Non-dynamic fibres, including intermediate filament-like structures, are known to occur in some bacteria.. Details of known filament structures are discussed and related to what has been established about their molecular mechanisms, including current controversies. The final chapter covers the use of some of these dynamic filaments in Systems Biology research. The level of information in all chapters is suitable both for active researchers and for advanced students in courses involving bacterial or archaeal physiology, molecular microbiology, structural cell biology, molecular motility or evolution. Chapter 3 of this book is open access under a CC BY 4.0 license.
Author: Xuedong Zhou
Publisher: Springer Nature
ISBN: 9811578990
Category : Medical
Languages : en
Pages : 368
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Book Description
This book is the second edition of Atlas of Oral Microbiology: From Healthy Microflora to Disease (ISBN 978-0-12-802234-4), with two new features: we add about 60 pictures of 14 newly isolated microbes from human dental plaque, at the same time, we re-organize the content of this book and provide more research progress about the oral microbiome bank of China, the invasion of oral microbiota into the gut, and the relationships between Oral Microflora and Human Diseases. This book is keeping up with the advanced edge of the international research field of oral microbiology. It innovatively gives us a complete description of the oral microbial systems according to different oral ecosystems. It collects a large number of oral microbial pictures, including cultural pictures, colonies photos, and electron microscopy photos. It is by far the most abundant oral microbiology atlas consists of the largest number of pictures. In the meantime, it also described in detail a variety of experimental techniques, including microbiological isolation, culture, and identification. It is an atlas with strong practical function. The editors and writers of this book have long been engaged in teaching and research work in oral microbiology and oral microecology. This book deserves a broad audience, and it will meet the needs of researchers, clinicians, teachers, and students major in biology, dental medicine, basic medicine, or clinical medicine. It can also be used to facilitate teaching and international academic exchanges.
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
Author: Samantha Fowler
Publisher:
ISBN: 9789888407453
Category : Science
Languages : en
Pages : 618
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Book Description
Concepts of Biology is designed for the single-semester introduction to biology course for non-science majors, which for many students is their only college-level science course. As such, this course represents an important opportunity for students to develop the necessary knowledge, tools, and skills to make informed decisions as they continue with their lives. Rather than being mired down with facts and vocabulary, the typical non-science major student needs information presented in a way that is easy to read and understand. Even more importantly, the content should be meaningful. Students do much better when they understand why biology is relevant to their everyday lives. For these reasons, Concepts of Biology is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand.We also strive to show the interconnectedness of topics within this extremely broad discipline. In order to meet the needs of today's instructors and students, we maintain the overall organization and coverage found in most syllabi for this course. A strength of Concepts of Biology is that instructors can customize the book, adapting it to the approach that works best in their classroom. Concepts of Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand--and apply--key concepts.
