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Janet L. Schottel

Bio: Janet L. Schottel is an academic researcher from University of Minnesota. The author has contributed to research in topics: Streptomyces scabies & Gene. The author has an hindex of 26, co-authored 62 publications receiving 2388 citations. Previous affiliations of Janet L. Schottel include Stanford University & University of Yamanashi.


Papers
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Journal ArticleDOI
TL;DR: Direct evidence was obtained for 3'-to-5' directionality in the decay of the long-lived mRNA encoded by the ompA gene, and no preferential stability was observed for translated versus untranslated mRNA segments.
Abstract: An assay was developed to investigate the fate of specific segments of beta-lactamase (bla) and ompA gene transcripts in Escherichia coli. DNA probes cloned in bacteriophage M13 were treated with an endonuclease capable of cleaving single-stranded DNA, the fragments produced were annealed with total cellular RNA, and the resulting RNA . DNA hybrids were subjected to S1 nuclease treatment and gel fractionation. By using this assay, direct evidence was obtained for 3'-to-5' directionality in the decay of the long-lived mRNA encoded by the ompA gene, and no preferential stability was observed for translated versus untranslated mRNA segments. In the case of bla mRNA, initial cleavage of the full-length transcript was rate limiting, and no decay intermediates were detected. No difference in degradation rate was seen for bla transcripts having variant 3' or 5' termini.

350 citations

Journal ArticleDOI
TL;DR: Two separate enzymes, which determine resistance to inorganic mercury and organomercurials, have been purified from the plasmid-bearing Escherichia coli strain J53-1(R831), suggesting that the native enzyme is composed of three identical subunits.

195 citations

Journal ArticleDOI
27 Sep 1974-Nature
TL;DR: THE AUTHORS have screened a large number of R plasmid-bearing Escherichia coli and obtained a few that confer resistance to the organomercurials phenylmercuric acetate (PMA) and methylmerCuric chloride (MMA), which are of interest to see if the mercury(ial) resistance of the bacteria in the alimentary canal influences the fate of ingested mercury(ials).
Abstract: WE have screened a large number of R plasmid-bearing Escherichia coli and obtained a few that confer resistance to the organomercurials phenylmercuric acetate (PMA) and methylmercuric chloride (MMA). Resistance to cationic Hg(II) in E. coli, Staphylococcus aureus and Pseudomonas aeruginosa has invariably been associated with plasmids that also mediate resistance to various antibiotics (R plasmids)1–6. The mechanism of mercury resistance, is the enzymatic reduction of Hg(II) to Hg(0), which is volatile2,7,8. Previously, no organomercurial-reducing E. coli strains have been reported. The only organomercurial-reducing strain studied in detail is a PMA-resistant soil pseu-domonad7–9. As organomercurials including PMA are a human health problem10, it will be of interest to see if the mercury(ial) resistance of the bacteria in our alimentary canal influences the fate of ingested mercury(ials).

175 citations

Journal ArticleDOI
10 Apr 1980-Nature
TL;DR: Selectable plasmid vectors that contain a gene encoding resistance to the antibiotic methylenomycin A and that are suitable for the cloning of endonuclease-generated DNA fragments in Streptomyces species have been constructed and characterised.
Abstract: Selectable plasmid vectors that contain a gene encoding resistance to the antibiotic methylenomycin A and that are suitable for the cloning of endonuclease-generated DNA fragments in Streptomyces species have been constructed and characterised.

160 citations

Journal ArticleDOI
TL;DR: The crystal structure of a novel esterase from Streptomyces scabies, a causal agent of the potato scab disease, was solved at 2.1 Å resolution and constitutes the first known natural variation of the chymotrypsin-like triad in which a carboxylic acid is replaced by a neutral hydrogen-bond acceptor.
Abstract: The crystal structure of a novel esterase from Streptomyces scabies , a causal agent of the potato scab disease, was solved at 2.1 A resolution. The tertiary fold of the enzyme is substantially different from that of the α/β hydrolase family and unique among all known hydrolases. The active site contains a dyad of Ser 14 and His 283, closely resembling two of the three components of typical Ser-His-Asp(Glu) triads from other serine hydrolases. Proper orientation of the active site imidazol is maintained by a hydrogen bond between the Nδ-H group and a main chain oxygen. Thus, the enzyme constitutes the first known natural variation of the chymotrypsin-like triad in which a carboxylic acid is replaced by a neutral hydrogen-bond acceptor.

143 citations


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Book
01 Jan 1979
TL;DR: This significant book provides not only an introduction to the dynamics of aquatic chem istries but also identifies those materials that jeopardize the resources of both the marine and fluvial domains.
Abstract: Aquatic chemistry is becoming both a rewarding and substantial area of inquiry and is drawing many prominent scientists to its fold. Its literature has changed from a compilation of compositional tables to studies of the chemical reactions occurring within the aquatic environments. But more than this is the recognition that human society in part is determining the nature of aquatic systems. Since rivers deliver to the world ocean most of its dissolved and particulate components, the interactions of these two sets of waters determine the vitality of our coastal waters. This significant vol ume provides not only an introduction to the dynamics of aquatic chem istries but also identifies those materials that jeopardize the resources of both the marine and fluvial domains. Its very title provides its emphasis but clearly not its breadth in considering natural processes. The book will be of great value to those environmental scientists who are dedicated to keeping the resources of the hydrosphere renewable. As the size of the world population becomes larger in the near future and as the uses of materials and energy show parallel increases, the rivers and oceans must be considered as a resource to accept some of the wastes of society. The ability of these waters and the sediments below them to accommodate wastes must be assessed continually. The key questions relate to the capacities of aqueous systems to carry one or more pollutants."

3,488 citations

Journal ArticleDOI
TL;DR: The presence and spread of antibiotic resistance in non-agricultural, non-clinical environments is explored and the need for more intensive investigation on this subject is demonstrated.
Abstract: Antibiotic-resistant pathogens are profoundly important to human health, but the environmental reservoirs of resistance determinants are poorly understood The origins of antibiotic resistance in the environment is relevant to human health because of the increasing importance of zoonotic diseases as well as the need for predicting emerging resistant pathogens This Review explores the presence and spread of antibiotic resistance in non-agricultural, non-clinical environments and demonstrates the need for more intensive investigation on this subject

1,850 citations

Journal ArticleDOI
TL;DR: Multiple microbial interactions involving bacteria and fungi in the rhizosphere are shown to provide enhanced biocontrol in many cases in comparison with biocOntrol agents used singly.
Abstract: The loss of organic material from the roots provides the energy for the development of active microbial populations in the rhizosphere around the root. Generally, saproptrophs or biotrophs such as mycorrhizal fungi grow in the rhizosphere in response to this carbon loss, but plant pathogens may also develop and infect a susceptible host, resulting in disease. This review examines the microbial interactions that can take place in the rhizosphere and that are involved in biological disease control. The interactions of bacteria used as biocontrol agents of bacterial and fungal plant pathogens, and fungi used as biocontrol agents of protozoan, bacterial and fungal plant pathogens are considered. Whenever possible, modes of action involved in each type of interaction are assessed with particular emphasis on antibiosis, competition, parasitism, and induced resistance. The significance of plant growth promotion and rhizosphere competence in biocontrol is also considered. Multiple microbial interactions involving bacteria and fungi in the rhizosphere are shown to provide enhanced biocontrol in many cases in comparison with biocontrol agents used singly. The extreme complexity of interactions that can occur in the rhizosphere is highlighted and some potential areas for future research in this area are discussed briefly.

1,818 citations

Journal ArticleDOI
TL;DR: The microbial basis of specific suppression to four diseases, Fusarium wilts, potato scab, apple replant disease, and take-all, is discussed and the microbial composition and complex interactions in suppressive soils are dissected.
Abstract: ▪ Abstract Agricultural soils suppressive to soilborne plant pathogens occur worldwide, and for several of these soils the biological basis of suppressiveness has been described. Two classical types of suppressiveness are known. General suppression owes its activity to the total microbial biomass in soil and is not transferable between soils. Specific suppression owes its activity to the effects of individual or select groups of microorganisms and is transferable. The microbial basis of specific suppression to four diseases, Fusarium wilts, potato scab, apple replant disease, and take-all, is discussed. One of the best-described examples occurs in take-all decline soils. In Washington State, take-all decline results from the buildup of fluorescent Pseudomonas spp. that produce the antifungal metabolite 2,4-diacetylphloroglucinol. Producers of this metabolite may have a broader role in disease-suppressive soils worldwide. By coupling molecular technologies with traditional approaches used in plant patholog...

1,573 citations

Journal ArticleDOI
TL;DR: In most natural environments, association with a surface in a structure known as a biofilm is the prevailing microbial lifestyle and is an efficient means of lingering in a favorable microenvironment rather than being swept away by the current.
Abstract: In most natural environments, association with a surface in a structure known as a biofilm is the prevailing microbial lifestyle. Surface association is an efficient means of lingering in a favorable microenvironment rather than being swept away by the current. Taken to the extreme, we may view the

1,455 citations