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Articles 1 - 7 of 7
Full-Text Articles in Life Sciences
Identification And Characterization Of Spcu, A Chaperone Required For Efficient Secretion Of The Exou Cytotoxin, Viviane Finck-Barbançon, Timothy L. Yahr, Dara W. Frank
Identification And Characterization Of Spcu, A Chaperone Required For Efficient Secretion Of The Exou Cytotoxin, Viviane Finck-Barbançon, Timothy L. Yahr, Dara W. Frank
Dartmouth Scholarship
In recent studies, we have shown that Pseudomonas aeruginosa strains that are acutely cytotoxic in vitro damage the lung epithelium in vivo. Genetic analysis indicated that the factor responsible for acute cytotoxicity was controlled by ExsA and therefore was part of the exoenzyme S regulon. The specific virulence determinant responsible for epithelial damage in vivo and cytotoxicity in vitro was subsequently mapped to the exoU locus. The present studies are focused on a genetic characterization of the exoU locus. Northern blot analyses and complementation experiments indicated that a region downstream of exoU was expressed and that the expression of this …
The Seca Subunit Of Escherichia Coli Preprotein Translocase Is Exposed To The Periplasm, Jerry Eichler, William Wickner
The Seca Subunit Of Escherichia Coli Preprotein Translocase Is Exposed To The Periplasm, Jerry Eichler, William Wickner
Dartmouth Scholarship
SecA undergoes conformational changes during translocation, inserting domains into and across the membrane or enhancing the protease resistance of these domains. We now show that some SecA bound at SecYEG is accessible from the periplasm to a membrane-impermeant probe in cells with a permeabilized outer membrane but an intact plasma membrane.
Characterization Of Metal-Regulated Genes In Pseudomonas Fluorescens, Melanie Pearson
Characterization Of Metal-Regulated Genes In Pseudomonas Fluorescens, Melanie Pearson
Honors Theses
One side effect of today's industrialized world is increased levels of heavy metals in the environment. Many of these metals are necessary for biological function as trace elements, but at higher concentrations are toxic. Other metals, such as cadmium, are not beneficial at any level, and have only deleterious effects on living organisms. Cadmium is primarily thought to interfere with normal biological function of proteins. Human exposure to cadmium appears to primarily damage the kidneys, but may also affect the liver, lungs, immune system, and central nervous system. Bacteria, however, have developed several methods for handling toxic heavy metals: cation …
Gene Expression In Two Cyanobacteria, Freshwater Synechococcus Sp. Pcc 7942 And Oceanic Synechococcus Sp. Wh 7803, In Response To Ammonium, Nitrate Or Iron, Abbas Sadeghi
Dissertations and Theses
The transcriptional response of freshwater Synechococcus sp. PCC 7942 and oceanic Synechococcus sp. WH 7803 to ammonium, nitrate or iron was studied in single or multiple factor limited cultures. Both strains showed maximum production of NiR mRNA when grown in nitrate-containing media. When grown in ammonium-containing medium, they did not show any signal for NiR mRNA synthesis. The influence on the transcription of NiR mRNA by iron as sole limiting nutrient was also evaluated. Iron increased the NiR mRNA whether or not the positive effect of nitrate was already present. The hybridization signal of mRNA for the large subunit of …
An Analysis Of Fecal Coliform Bacteria As A Water Quality Indicator, Janet Heyl Vail
An Analysis Of Fecal Coliform Bacteria As A Water Quality Indicator, Janet Heyl Vail
Dissertations
The focus of this study is to assess the efficacy of fecal coliform bacteria as a microbiological water quality indicator. The scientific and educational context of fecal coliform bacteria is explored through analysis of large sets of water quality data, focused field monitoring projects, and review of commonly used resources for school-based and volunteer water-related studies. Analyzed data sets include long term sampling (10 years), multiple sites, daily samples, storm event samples, and other parameters monitored in parallel with bacteria. Special attention is given to data sets from Kent County, Michigan. A background reference site in Michigan unimpacted by humans …
A New Genetic Locus In Sinorhizobium Meliloti Is Involved In Stachydrine Utilization, Donald A. Phillips Dr., Eve S. Sandee Dr., Jan A.C. Vriezen Dr., Frans J. Debruijn Dr., Daniel Lerudulier Dr., Cecillia M. Joseph Dr.
A New Genetic Locus In Sinorhizobium Meliloti Is Involved In Stachydrine Utilization, Donald A. Phillips Dr., Eve S. Sandee Dr., Jan A.C. Vriezen Dr., Frans J. Debruijn Dr., Daniel Lerudulier Dr., Cecillia M. Joseph Dr.
Jan A.C. Vriezen Dr.
Stachydrine, a betaine released by germinating alfalfa seeds, functions as an inducer of nodulation genes, a catabolite, and an osmoprotectant in Sinorhizobium meliloti. Two stachydrine-inducible genes were found in S. meliloti 1021 by mutation with a Tn5-luxAB promoter probe. Both mutant strains (S10 and S11) formed effec- tive alfalfa root nodules, but neither grew on stachydrine as the sole carbon and nitrogen source. When grown in the absence or presence of salt stress, S10 and S11 took up [14C]stachydrine as well as wild-type cells did, but neither used stachydrine effectively as an osmoprotectant. In the absence of salt stress, both …
Cyanonews (Vol. 14, No. 1, August 1998), Jeff Elhai
Cyanonews (Vol. 14, No. 1, August 1998), Jeff Elhai
CyanoNews
CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.