Author: Daniel Fernando Rojas Tapias
Publisher:
ISBN:
Category :
Languages : en
Pages : 398

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Author: Smarajit Mondal
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Transcription in bacteria is regulated at the level of initiation, elongation and termination. Although the regulation of transcriptional initiation is well studied, the regulation of elongation and termination are not well understood. This thesis focuses on understanding the role of NusA on intrinsic termination and the role of NusG on RNA polymerase pausing using genomic, biochemical and computational analyses. Tight regulation of transcription termination is required to maintain proper levels of gene expression in bacteria, because termination failure abolishes operon boundaries, leading to misregulation of downstream genes. NusA is a negative transcription elongation factor that was known to cause a slight stimulation of termination at intrinsic terminators in vitro, but its impact on termination and global gene expression in vivo was not known. In this thesis, I describe the mapping of intrinsic terminators genome wide in B subtilis and measure the effect of NusA on the efficiency of these terminators in vivo using a novel high resolution 3' end-mapping technique coupled with mRNA profiling. Based on these studies, I report the existence of a subclass of previously unidentified pseudo-intrinsic terminators that are dependent on NusA for termination. Sequence comparison of different terminators reveals that weak hairpins and/or distal U-tract interruptions favors NusA-dependent termination, supporting a model in which NusA assists hairpin folding and slows down RNA polymerase near the termination window. These studies also revealed that readthrough of NusA-dependent terminators increases transcription of genes related to replication and DNA metabolism, suggesting a role of NusA in maintaining genome stability. I further show that nusA is autoregulated by a transcription attenuation mechanism that does not rely on antiterminator structures to prevent termination. Instead, NusA-stimulated termination in its 5'UTR dictates the extent of transcription into the operon. Another major focus of this thesis is to understand the regulation of transcription elongation by NusG-stimulated pausing of RNA polymerase. NusG is a positive elongation factor in E. coli that accelerates transcription by reducing the dwell time of RNA polymerase at pause sites. In B. subtilis, NusG stimulates pausing at positions U107 and U144 in the trp-leader transcript. NusG-stimulated pausing at U144 requires a short sequence in the non-template DNA strand and participates in the TRAP-dependent translation repression mechanism. In this thesis, I report the characterization of the NusG-stimulated U107 pause signal and show that disruption of the NusG recognition motif dramatically reduces pausing. These results suggest a mechanism in which RNA polymerase pausing at this site participates in the transcription attenuation mechanism by increasing additional time for TRAP binding to the nascent transcript.

Author: Peter Zuber
Publisher: Springer Science & Business Media
ISBN: 1461469252
Category : Medical
Languages : en
Pages : 53

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This SpringerBrief on Spx reviews the investigations that led to the discovery of Spx and its orthologs and ties together the results of various studies that have explored the function and control of spx in Gram-positive organisms. Spx of Bacillus subtilis has been extensively studied, but very little has been published about it. This book incorporates a number of studies that have been conducted in other Gram positive bacteria, which examined the role of Spx orthologs in stress response, bacterial development and virulence. The book contains an overview that will introduce the protein and its orthologous forms, its association with RNA polymerase, the species of Gram-positive bacteria in which it is found, and the conditions in which it is abundant and active. Spx is a member of a large group of proteins belonging to the ArsC/Spx protein family, so the review touches upon the bioinformatic support for the protein family composition and its meaning with regard to protein structure/function. ​

Author: Biswarup Mukhopadhyay
Publisher: Frontiers Media SA
ISBN: 283250180X
Category : Science
Languages : en
Pages : 175

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Author: Yi-Wei Tang
Publisher: Academic Press
ISBN: 0323899927
Category : Science
Languages : en
Pages : 3535

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Book Description
Molecular Medical Microbiology, Third Edition presents the latest release in what is considered to be the first book to synthesize new developments in both molecular and clinical research. The molecular age has brought about dramatic changes in medical microbiology, along with great leaps in our understanding of the mechanisms of infectious disease. This third edition is completely updated, reviewed and expanded, providing a timely and helpful update for microbiologists, students and clinicians in the era of increasing use of molecular techniques, changing epidemiology and prevalence, and increasing resistance of many pathogenic bacteria. Written by experts in the field, chapters include cutting-edge information and clinical overviews for each major bacterial group, along with the latest updates on vaccine development, molecular technology and diagnostic technology. - Completely updated and revised edition of this comprehensive and accessible reference on molecular medical microbiology - Includes full color presentations throughout - Delves into in-depth discussions on individual pathogenic bacteria in a system-oriented approach - Includes a clinical overview for each major bacterial group - Presents the latest information on vaccine development, molecular technology and diagnostic technology - Provides more than 100 chapters on all major groups of bacteria

Author: Walid El-Sharoud
Publisher: Springer Science & Business Media
ISBN: 3540749217
Category : Science
Languages : en
Pages : 377

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Book Description
The application of new molecular methodologies in the study of bacterial behavior and cell architecture has enabled new revolutionary insights and discoveries in these areas. This new text presents recent developments in bacterial physiology that are highly relevant to a wide range of readership including those interested in basic and applied knowledge. Its chapters are written by international scientific authorities at the forefront of the subject. The value of this recent knowledge in bacterial physiology is not only restricted to fundamental biology. It also extends to biotechnology and drug-discovery disciplines.

Author:
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 2036

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

Author: Wayne Russell
Publisher: Karger Medical and Scientific Publishers
ISBN: 3805577869
Category : Medical
Languages : en
Pages : 287

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Book Description
Over the past few decades the increase in bacterial resistance has led to the search for novel antibacterial therapies and a better understanding of virulence mechanisms used by pathogens. It has been shown that the interplay between pathogenic bacteria and the host is complex and finely balanced. Successful pathogens can manipulate host homeostasis and normal cell functions using a variety of molecular strategies. This volume of the Karger book series Contributions to Microbiology summarizes some of the most important bacterial virulence mechanisms. Eminent scientists provide an update on recent findings in their fields. This state-of-the-art account will not only attract the interest of clinical and preclinical researchers, but will also be of great value to students with an interest in medicine, biology, chemistry, and infectious diseases.

Author: Robert K. Poole
Publisher: Academic Press
ISBN: 0128177152
Category : Science
Languages : en
Pages : 402

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Book Description
Advances in Microbial Physiology, Volume 75, the latest release in this ongoing series, continues the long tradition of topical, important, cutting-edge reviews in microbiology. The book contains updates in the field, with comprehensive chapters covering, Sulfoxides in bacterial systems, RNA degradosomes and control by signals including c-di-GMP, Protein nanowires: biological function and synthetic constructs for 'Green' electronics, Bacterial nitrous oxide respiration: electron transport chains and copper transfer reactions, Multiple degrees of separation in the central pathways of the catabolism of aromatic compounds in Dikarya fungi, and more. - Contains contributions from leading authorities in microbial physiology - Informs and updates on all the latest developments in the field of microbial physiology

Author: Dörte Becher
Publisher: Humana
ISBN: 9781493993680
Category : Science
Languages : en
Pages : 344

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Book Description
This detailed volume explores state-of-the-art methods for the identification, quantification, and characterization of microbial proteins. Split into five parts, the content addresses global sample preparation and protein enrichment, subcellular fractionation, protein quantification, analysis of post-translational protein modifications, as well as metaproteomics, a relatively new branch of microbial proteomics that investigates the proteins of all microbes comprising an environmental consortium. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Microbial Proteomics: Methods and Protocols serves as a valuable and stimulating source for all beginners and advanced researchers in the field of microbial proteomics and beyond. Chapter 18 is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.