RNA
More general concepts than this:
More specific concepts than this:
Filter by:
Content Type:
- Chapter [58] http://www.w3.org/1999/02/22-rdf-syntax-ns#type http://pub2web.metastore.ingenta.com/ns/Chapter
- Article [22] http://www.w3.org/1999/02/22-rdf-syntax-ns#type http://pub2web.metastore.ingenta.com/ns/Article
- Frontmatter [9] http://www.w3.org/1999/02/22-rdf-syntax-ns#type http://pub2web.metastore.ingenta.com/ns/Frontmatter
- Backmatter [6] http://www.w3.org/1999/02/22-rdf-syntax-ns#type http://pub2web.metastore.ingenta.com/ns/Backmatter
- MagazineArticle [5] http://www.w3.org/1999/02/22-rdf-syntax-ns#type http://pub2web.metastore.ingenta.com/ns/MagazineArticle
- Continuous Publication Journal [2] http://www.w3.org/1999/02/22-rdf-syntax-ns#type http://pub2web.metastore.ingenta.com/ns/ContinuousPublicationArticle
- Contributors [1] http://www.w3.org/1999/02/22-rdf-syntax-ns#type http://pub2web.metastore.ingenta.com/ns/Contributors
Publication Date:
- 2017 [2] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2017
- 2016 [4] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2016
- 2015 [3] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2015
- 2014 [2] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2014
- 2012 [2] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2012
- 2011 [2] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2011
- 2010 [1] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2010
- 2008 [8] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2008
- 2007 [5] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2007
- 2006 [1] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2006
- 2005 [1] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2005
- 2004 [2] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2004
- 2003 [2] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2003
- 2002 [2] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2002
- 2000 [2] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 2000
- 1999 [3] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 1999
- 1998 [8] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 1998
- 1995 [3] http://pub2web.metastore.ingenta.com/ns/yearOfPublication 1995
- See more... Hide...
-
A Hands-On Activity to Demonstrate the Central Dogma of Molecular Biology Via a Simulated VDJ Recombination Activity †
- Author: Pamela A. Marshall
-
Citation: Marshall P. 2017. A hands-on activity to demonstrate the central dogma of molecular biology via a simulated vdj recombination activity † . 18(2): doi:10.1128/jmbe.v18i2.1277
- DOI 10.1128/jmbe.v18i2.1277
- More Less
-
Abstract:
Essential or enduring understandings are often defined as the underlying core concepts or “big ideas” we’d like our students to remember when much of the course content has been forgotten. The central dogma of molecular biology and how cellular information is stored, used, and conveyed is one of the essential understandings students should retain after a course or unit in molecular biology or genetics. An additional enduring understanding is the relationships between DNA sequence, RNA sequence, mRNA production and processing, and the resulting polypeptide/protein product. A final big idea in molecular biology is the relationship between DNA mutation and polypeptide change. To engage students in these essential understandings in a Genetics course, I have developed a hands-on activity to simulate VDJ recombination. Students use a foldable type activity to splice out regions of a mock kappa light chain gene to generate a DNA sequence for transcription and translation. Students fold the activity several different times in multiple ways to “recombine” and generate several different DNA sequences. They then are asked to construct the corresponding mRNA and polypeptide sequence of each “recombined” DNA sequence and reflect on the products in a write-to-learn activity.
-
siRNA Immunological Fishing Training (SIFT) Experience as a Novel Research Education Tool for Students Studying Immunology †
- Authors: Diana M. Elizondo, Temesgen E. Andargie, Dineeta S. Kubhar, Karis M. Marshall, Aamir M. Zariwala, Clarence M. Lee, Michael W. Lipscomb*
-
Citation: Elizondo D, Andargie T, Kubhar D, Marshall K, Zariwala A, Lee C, Lipscomb M. 2017. Sirna immunological fishing training (sift) experience as a novel research education tool for students studying immunology † . 18(1): doi:10.1128/jmbe.v18i1.1288
- DOI 10.1128/jmbe.v18i1.1288
- More Less
-
Abstract:
This report describes an innovative research education tool for student exposure and training in immunology. Utilizing the wealth of transcriptomics data provided through the immunological genome project, graduate and undergraduate students can engage in hands-on experimental studies to identify and rigorously characterize novel genes in immune cells using RNA interference-mediated approaches. The SIFT activities are directly aligned with cell biology and immunology courses and serve to reinforce and expand on the foundations learned. Furthermore, the student-driven studies provide a sense of ownership and largely expose students to the breadth of experimental research approaches in the biological sciences. Finally, generation of original datasets supports the greater scientific community by contributing in assembly and delineation of the regulatory networks that govern immunity.
-
Tracking the Resolution of Student Misconceptions about the Central Dogma of Molecular Biology †
- Authors: Amy G. Briggs*, Stephanie K. Morgan, Seth K. Sanderson, Molly C. Schulting, Laramie J. Wieseman
-
Citation: Briggs A, Morgan S, Sanderson S, Schulting M, Wieseman L. 2016. Tracking the resolution of student misconceptions about the central dogma of molecular biology † . 17(3):339-350 doi:10.1128/jmbe.v17i3.1165
- DOI 10.1128/jmbe.v17i3.1165
- More Less
-
Abstract:
The goal of our study was to track changes in student understanding of the central dogma of molecular biology before and after taking a genetics course. Concept maps require the ability to synthesize new information into existing knowledge frameworks, and so the hypothesis guiding this study was that student performance on concept maps reveals specific central dogma misconceptions gained, lost, and retained by students. Students in a genetics course completed pre- and posttest concept mapping tasks using terms related to the central dogma. Student maps increased in complexity and validity, indicating learning gains in both content and complexity of understanding. Changes in each of the 351 possible connections in the mapping task were tracked for each student. Our students did not retain much about the central dogma from their introductory biology courses, but they did move to more advanced levels of understanding by the end of the genetics course. The information they retained from their introductory courses focused on structural components (e.g., protein is made of amino acids) and not on overall mechanistic components (e.g., DNA comes before RNA, the ribosome makes protein). Students made the greatest gains in connections related to transcription, and they resolved the most prior misconceptions about translation. These concept-mapping tasks revealed that students are able to correct prior misconceptions about the central dogma during an intermediate-level genetics course. From these results, educators can design new classroom interventions to target those aspects of this foundational principle with which students have the most trouble.
-
Small Things Considered
- Author: Christoph Weigel
- Publication Date : September 2016
- More Less
-
Author: Christoph WeigelAbstract:
At the heart of every cell's “operating system” are the ribosomes: ingenious nanomachines that translate messenger RNA (mRNA) into proteins that cells need to build and maintain themselves. Ribosomes were first described by the electron microscopist George Palade in a 1955 paper, in which he contemplated the electron dense particles lining the endoplasmic reticulum of rat pancreas cells: “The relationship between the membrane of the endoplasmic reticu-lum and the small granules deserves special consideration.” Indeed, they deserved and got consideration: today PubMed lists over 50,000 papers dealing with ribosomes—comparable to the number of ribosomes in rapidly grow-ing E. coli cells. With such numbers, it's no wonder cells spend roughly 2/3 of their energy budget on the synthesis of ribosomes and translation!
-
Small RNAs Regulate Bacteroides Nutrient Use
- Publication Date : August 2016
- More Less
-
Research published in the Journal of Bacteriology demonstrates that a system of small RNAs help regulate the genetic regions called polysaccharide utilization loci (PULs) in the human gut-residing Bacteroides genus. First author Yanlu Cao and senior author C. Jeffrey Smith found that a small antisense RNA (sRNA) gene, donS, regulates activity of the don (for deglycosylation of N-glycans) locus. These sRNAs help the bacterium respond to multiple nutrient sources and may act as a regulatory mechanism to quickly modify gene expression under quickly changing nutrient conditions. The research was a collaboration between East Carolina University in Greenville, NC, and the University of Wúrzburg in Wúrzburg, Germany.
-
Games that Enlist Collective Intelligence to Solve Complex Scientific Problems
- Authors: Stephen Burnett, Michelle Furlong, Paul Guy Melvin, Richard Singiser*
-
Citation: Burnett S, Furlong M, Melvin P, Singiser R. 2016. Games that enlist collective intelligence to solve complex scientific problems. 17(1):133-136 doi:10.1128/jmbe.v17i1.983
- DOI 10.1128/jmbe.v17i1.983
- More Less
-
Abstract:
There is great value in employing the collective problem-solving power of large groups of people. Technological advances have allowed computer games to be utilized by a diverse population to solve problems. Science games are becoming more popular and cover various areas such as sequence alignments, DNA base-pairing, and protein and RNA folding. While these tools have been developed for the general population, they can also be used effectively in the classroom to teach students about various topics. Many games also employ a social component that entices students to continue playing and thereby to continue learning. The basic functions of game play and the potential of game play as a tool in the classroom are discussed in this article.
-
Outbreak Spurred Several Approaches to Developing Ebola Therapeutic Products
- Author: Jeffrey L. Fox
- Publication Date : July 2015
- More Less
-
Author: Jeffrey L. FoxAbstract:
Several distinct types of Ebola therapeutic products are under development—some more or less conventional antiviral agents, while others depend on more recently developed techniques to disrupt viral gene activity or use antibodies to bind the virus and trigger host immune responses.
-
Archaellum Moves Archaea with Distinction
- Authors: Sonja-Verena Albers, and Ken F. Jarrell
- Publication Date : July 2015
- More Less
-
Authors: Sonja-Verena Albers, and Ken F. JarrellAbstract:
Cell motility in pure cultures of halophilic archaea was first observed almost a century ago and, in methanogens, at least as long ago as 1951, when Methanococcus vannielii was first isolated. Although M. vannielii was reported as being motile, no flagella were observed until nearly three decades later. Other researchers from that era reported seeing fimbriae (pili) or flagella on a variety of different archaea, including methanogens, halophiles, and Sulfolobus. However, during that period the members of the archaea were still considered bacteria, predating the groundbreaking realignment of the tree of life into the three domains of Archaea, Bacteria, and Eukarya by Carl Woese.
-
The Joint Genome Institute Offers Resources Beyond a Core Facility
- Authors: David Gilbert, Nikos Kyrpides, Susannah Tringe, Axel Visel, and Tanja Woyke
- Publication Date : July 2015
- More Less
-
Authors: David Gilbert, Nikos Kyrpides, Susannah Tringe, Axel Visel, and Tanja WoykeAbstract:
The U.S. Department of Energy (DOE) Joint Genome Institute (JGI) was established in 1997 to consolidate the department's programs and resources in DNA sequencing, informatics, and technology development. Soon after, the University of California, which manages the Lawrence Berkeley National Laboratory, where JGI was first situated, leased lab and office space in nearby Walnut Creek to house JGI activities. The early focus for JGI was the Human Genome Project. After its scientists completed their sequencing of three human chromosomes, however, JGI broadened its mandate in 2004 to become a national user facility, which now boasts thousands of users worldwide.
-
Teaching Responsible Conduct Responsibly a
- Authors: Michael J. Zigmond*, Beth A. Fischer
-
Citation: Zigmond M, Fischer B. 2014. Teaching responsible conduct responsibly a . 15(2):83-87 doi:10.1128/jmbe.v15i2.874
- DOI 10.1128/jmbe.v15i2.874
- More Less
-
Abstract:
Requirements for educating the next generation of scientists in the responsible conduct of research (RCR) were published approximately 25 years ago. Over the years, an extensive collThe advancement of science requires trust – trust in the literature, in our collaborators, in the data we are handed, and most of all in ourselves. Policies issued by U.S. federal funding agencies (e.g., the National Institutes of Health and National Science Foundation) have been valuable in prompting institutions to initiate formal mechanisms for providing instruction in the responsible conduct of research (RCR). However, the guidelines vary greatly in scope, detail, and the types of individuals to which they apply. Unfortunately, at many institutions, the provision of RCR instruction has become a bureaucratic exercise aimed at fulfilling a regulatory requirement, instead of an activity optimized for promoting a climate of integrity. We argue that for RCR instruction to be effective it should (1) be provided to everyone involved in the research enterprise, be they students, trainees, faculty, or staff, (2) be infused throughout one’s time at an institution. For graduate students, that would include from orientation to thesis completion, including integration into all “core classes” within their discipline, as well as into discussions at research group meetings. (3) We also advocate that the bulk of the instruction should be provided primarily by active researchers who know the issues and have relevance to, and credibly with, those being taught, and (4) that the instruction actively engages the learners. Not only will we be providing RCR instruction in a much more optimized manner, such an approach also emphasizes through our actions, not just in words, that behaving responsibly is an essential skill for researchers
-
Nus Factors of Escherichia coli
- Authors: Ranjan Sen, Jisha Chalissery, M. Zuhaib Qayyum, V. Vishalini, and Ghazala Muteeb
-
Citation: Sen R, Chalissery J, Qayyum M, Vishalini V, Muteeb G. 2014. Nus Factors of Escherichia coli, EcoSal Plus 2014; doi:10.1128/ecosalplus.ESP-0008-2013
- DOI 10.1128/ecosalplus.ESP-0008-2013
- More Less
-
Abstract:
The highly conserved Nus factors of bacteria were discovered as essential host proteins for the growth of temperate phage λ in Escherichia coli. Later, their essentiality and functions in transcription, translation, and, more recently, in DNA repair have been elucidated. Close involvement of these factors in various gene networks and circuits is also emerging from recent genomic studies. We have described a detailed overview of their biochemistry, structures, and various cellular functions, as well as their interactions with other macromolecules. Towards the end, we have envisaged different uncharted areas of studies with these factors, including their participation in pathogenicity.
-
Teaching the Central Dogma of Molecular Biology using Jewelry †
- Author: Jennifer M. DeBruyn
-
Citation: DeBruyn J. 2012. Teaching the central dogma of molecular biology using jewelry † . 13(1):62-64 doi:10.1128/jmbe.v13i1.356
- DOI 10.1128/jmbe.v13i1.356
- More Less
-
Abstract:
”Cracking the Code” is an activity developed to demonstrate the processes of transcription and translation. This hands-on activity helps students understand the relationship between form (base pairing) and function (information storage and transfer) of nucleic acids. In this activity, students go through the processes of transcription and translation of a DNA molecule to create jewelry; a beaded bracelet or necklace is used as a tactile representation of a chain of amino acids. To determine the correct order of “amino acid” beads, students must first decode a strand of DNA using complementary base pairing rules. The decoding is a two-step process that illustrates transcription (the copying of DNA to RNA) and translation (using tRNAs to match the genetic code to the correct amino acid). This teaches the relationship between structure (base pairs) and function (information storage and transfer) in nucleic acids.
-
Microbial Symbiosis and Evolution
- Author: Nancy A. Moran
-
Source: Microbes and Evolution , pp 191-196
Publication Date :
January 2012
- More Less
-
Abstract:
This chapter talks about the symbiosis of microbes and mitochondria. Mutations, including deletions of DNA, happen constantly, so the unused genes have long since disappeared from the genomes of mitochondria that inhabit our cells. In fact, mutations are still raining down on the genomes of our mitochondria, and these continue throughout our lives, contributing to various diseases and disorders. These malfunctions are the main reason we even think about our mitochondria. Another reason the mitochondria can live with so few genes is that many of the ancient genes of the mitochondrial ancestor have changed addresses, moving from the chromosome of the mitochondrion to our own chromosomes but sending their working products back to the mitochondrial homeland to carry out needed work. Some symbiotic bacteria have fewer than 200 genes, and the symbionts we call organelles can have even fewer, as in our own mitochondria with their miserly 15. Buchnera uses its ancestral genes for making the amino acids tryptophan and leucine, which are nutrients that a host needs. But these genes have been copied many times on tiny extra chromosomes (plasmids), an arrangement that allows hyperproduction of the amino acid products. Both symbionts and domesticated breeds can evolve extreme features over short periods on an evolutionary time scale. These extremes are produced mostly by exaggerating some functions, rather than by acquiring anything truly novel. And just like our domesticated animals and plants, symbionts themselves can be large, typically much larger than their free-living wild relatives.
-
Escherichia coli and the Emergence of Molecular Biology
- Author: Agnes Ullmann
-
Citation: Ullmann A. 2011. Escherichia coli and the Emergence of Molecular Biology, EcoSal Plus 2011; doi:10.1128/ecosalplus.1.1.2
- DOI 10.1128/ecosalplus.1.1.2
- More Less
-
Abstract:
The creation of the "Phage group" by M. Delbrück, S. E. Luria, and A. D. Hershey in 1940 at Cold Spring Harbor played a crucial role in the development of molecular biology. In the 1940s, working with Escherichia coli and its viruses, Luria and Delbrück discovered the spontaneous nature of bacterial mutations and Hershey described recombination in bacteriophages and demonstrated with M. Chase that the genetic material that infects bacteria is DNA. At the same time, S. Benzer defined the structure of a functional genetic unit and J. Lederberg and E. Tatum discovered sexual recombination between bacteria. Some years later, Lederberg's group discovered extrachromosomal particles, the plasmids, and a novel way of genetic transfer through bacteriophages, called transduction. In 1949, at the Pasteur Institute in Paris, A. Lwoff uncovered the mechanism of lysogeny. Shortly afterwards, F. Jacob and E. Wollman unraveled the mechanism of the sexual process in E. coli and established the circularity of the bacterial chromosome. In the 1960s, J. Monod and F. Jacob, by genetic analysis of the E. coli lactose system, proposed the operon model for gene regulation and introduced the concept of messenger RNA. The elucidation of the double helix structure of DNA in 1953 by F. Crick and J. Watson had major consequences: the establishment of the copying mechanism (Meselson and Stahl), the discovery of the nature of the genetic code (S. Brenner) leading to its deciphering. E. coli and its phages were instrumental in the development of recombinant DNA technology based on the discovery of the restriction-modification system by W. Arber.
-
John Roth’s Paths and Pathways *
- Authors: Kelly T. Hughes, Stanley Maloy
-
Source: The Lure of Bacterial Genetics , pp 3-7
Publication Date :
January 2011
- More Less
-
Abstract:
Bacterial genetics has been strongly influenced by the work of John Roth and his laboratory. Work in John’s laboratory has covered a large number of topics, beginning with the genetic regulation of the histidine (his) biosynthetic operon and extending to many other metabolic pathways and genetic processes. John became interested in bacterial genetics while an undergraduate at Harvard University. The regulatory mutations were scattered widely around the genome and affected functions involved in translation (e.g., histidyl-tRNA synthetase, tRNAHis, and tRNA modifying and processing enzymes). Interest in genetics of tRNA led John’s lab to work on a variety of informational suppressors, including recessive nonsense suppressors and many classes of frameshift suppressors in which altered tRNAs caused translation to shift reading phase. John became interested in chromosomal duplications during early studies on nonsense suppressor tRNAs. Suppressor mutations that alter an essential tRNA type are lethal unless they arise in one copy of a preexisting duplication of the tRNA gene. The genetic tools developed in John’s lab helped change the perspectives on the pulsating rhythms of chromosome organization. Other work led to ideas on the evolution of bacterial operons by horizontal transfer and origins of new genes by selective amplification. In addition to his research accomplishments, John is an enthusiastic, stimulating speaker and teacher.
-
Nucleic Acid Isolation: Overview of Sample Preparation Methods
- Author: Charles E. Hill
-
Source: Molecular Microbiology , pp 119-125
Publication Date :
January 2011
- More Less
-
Abstract:
The type of sample being submitted for analysis determines the method used for nucleic acid isolation. Serum is also an acceptable material and yields similar clinical utility, but viral quantification may be slightly lower than plasma from the same patient due to entrapment of some extracellular virus within the blood clot. Regardless of the source, nucleic acid extraction usually consists of three primary processes: (i) lysis, (ii) denaturation/degradation of other biomolecules, and (iii) separation of the nucleic acids from other constituents in the sample and/or concentration of the DNA or RNA. Although there are several possible ways to classify nucleic acid extraction techniques, the following types of chemistries are the most commonly used: (i) precipitative methods, (ii) liquid-phase extractions, and (iii) solid-phase extractions. Although all three types of extraction methods are used, solid-phase extractions now are the most widely utilized due to easy scalability and the availability of automated instruments for these methods. While precipitative and liquid-phase extraction methods are still widely used, the most commonly performed DNA and RNA extractions involve selective binding of nucleic acids to an immobilized matrix (solid phase). The majority of the alcohol can be removed by essentially drying the matrix with the nucleic acid bound. Automation of the nucleic acid extraction process typically provides a more reproducible yield of DNA and/or RNA.
-
A Glance Toward the Future: Where Do We Go from Here?
- Author: Kenneth Nealson
-
Source: Stable Isotope Probing and Related Technologies , pp 333-336
Publication Date :
January 2011
- More Less
-
Abstract:
In environments where growth can be fast and production of proteins and metabolites is rapid, the stable isotope probing (SIP) approach is at its best. Rapid incorporation of stable isotopes into DNA, RNA, protein, and/or metabolites will be used routinely in medical and dental research, perhaps drawing these fields far closer toward environmental microbiology than they have been in the past. Eukaryotes evolved in a sea of Bacteria and Archaea, and it would be astounding if there were not many interdependent metabolic interactions that describe the total organism as a eukaryotic/bacterial/archaeal conglomerate. This understanding will be one of the great accomplishments of the next decades and will be greatly enhanced by SIP technologies at nearly every level (DNA, RNA, protein, and metabolites). The differences between hydrogen transfer and electron transfer could be significant and offer some major challenges to the understanding of microbial ecology: challenges that may be solved in part via the application of SIP approaches and others that will require new ways of thinking and experimentation. Several papers have appeared recently on extracellular electron transport. It is clear from the work in several laboratories that microbes have mechanisms available to them to donate electrons directly to solid surfaces and to take electrons directly from solid surfaces raising the possibility that an energy realm previously not thought possible by most microbiologists could exist in sedimentary environments, utilizing various types of extracellular electron transport mechanisms to deliver energy in the form of electrons among energy sources, cells, and electron acceptors.
-
COLOR PLATES
- Publication Date : January 2011
- More Less
-
No descriptions available.
-
Initiation of DNA Replication
- Authors: Alan C. Leonard, and Julia E. Grimwade
-
Citation: Leonard A, Grimwade J. 2010. Initiation of DNA Replication, EcoSal Plus 2010; doi:10.1128/ecosalplus.4.4.1
- DOI 10.1128/ecosalplus.4.4.1
- More Less
-
Abstract:
In recent years it has become clear that complex regulatory circuits control the initiation step of DNA replication by directing the assembly of a multicomponent molecular machine (the orisome) that separates DNA strands and loads replicative helicase at oriC, the unique chromosomal origin of replication. This chapter discusses recent efforts to understand the regulated protein-DNA interactions that are responsible for properly timed initiation of chromosome replication. It reviews information about newly identified nucleotide sequence features within Escherichia coli oriC and the new structural and biochemical attributes of the bacterial initiator protein DnaA. It also discusses the coordinated mechanisms that prevent improperly timed DNA replication. Identification of the genes that encoded the initiators came from studies on temperature-sensitive, conditional-lethal mutants of E. coli, in which two DNA replication-defective phenotypes, "immediate stop" mutants and "delayed stop" mutants, were identified. The kinetics of the delayed stop mutants suggested that the defective gene products were required specifically for the initiation step of DNA synthesis, and subsequently, two genes, dnaA and dnaC, were identified. The DnaA protein is the bacterial initiator, and in E. coli, the DnaC protein is required to load replicative helicase. Regulation of DnaA accessibility to oriC, the ordered assembly and disassembly of a multi-DnaA complex at oriC, and the means by which DnaA unwinds oriC remain important questions to be answered and the chapter discusses the current state of knowledge on these topics.
-
Modulation of Chemical Composition and Other Parameters of the Cell at Different Exponential Growth Rates
- Authors: Hans Bremer, and Patrick P. Dennis
-
Citation: Bremer H, Dennis P. 2008. Modulation of Chemical Composition and Other Parameters of the Cell at Different Exponential Growth Rates, EcoSal Plus 2008; doi:10.1128/ecosal.5.2.3
- DOI 10.1128/ecosal.5.2.3
- More Less
-
Abstract:
This review begins by briefly presenting the history of research on the chemical composition and other parameters of cells of E. coli and S. enterica at different exponential growth rates. Studies have allowed us to determine the in vivo strength of promoters and have allowed us to distinguish between factor-dependent transcriptional control of the promoter and changes in promoter activity due to changes in the concentration of free functional RNA polymerase associated with different growth conditions. The total, or bulk, amounts of RNA and protein are linked to the growth rate, because most bacterial RNA is ribosomal RNA (rRNA). Since ribosomes are required for protein synthesis, their number and their rate of function determine the rate of protein synthesis and cytoplasmic mass accumulation. Many mRNAs made in the presence of amino acids have strong ribosome binding sites whose presence reduces the expression of all other active genes. This implies that there can be profound differences in the spectrum of gene activities in cultures grown in different media that produce the same growth rate. Five classes of growth-related parameters that are generally useful in describing or establishing the macromolecular composition of bacterial cultures are described in detail in this review. A number of equations have been reported that describe the macromolecular composition of an average cell in an exponential culture as a function of the culture doubling time and five additional parameters: the C- and D-periods, protein per origin (PO), ribosome activity, and peptide chain elongation rate.