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Full-Text Articles in Life Sciences

Novel Small Rnas Expressed By Bartonella Bacilliformis Under Multiple Conditions Reveal Potential Mechanisms For Persistence In The Sand Fly Vector And Human Host, Shaun Wachter, Linda D. Hicks, Rahul Raghavan, Michael F. Minnick Nov 2020

Novel Small Rnas Expressed By Bartonella Bacilliformis Under Multiple Conditions Reveal Potential Mechanisms For Persistence In The Sand Fly Vector And Human Host, Shaun Wachter, Linda D. Hicks, Rahul Raghavan, Michael F. Minnick

Biology Faculty Publications and Presentations

Bartonella bacilliformis, the etiological agent of Carrión’s disease, is a Gram-negative, facultative intracellular alphaproteobacterium. Carrión’s disease is an emerging but neglected tropical illness endemic to Peru, Colombia, and Ecuador. B. bacilliformis is spread between humans through the bite of female phlebotomine sand flies. As a result, the pathogen encounters significant and repeated environmental shifts during its life cycle, including changes in pH and temperature. In most bacteria, small non-coding RNAs (sRNAs) serve as effectors that may post-transcriptionally regulate the stress response to such changes. However, sRNAs have not been characterized in B. bacilliformis, to date. We …


Direct Binding Of Tfeα Opens Dna Binding Cleft Of Rna Polymeras, Sung-Hoon Jun, Jaekyung Hyun, Hoyoung Kim, Michael S. Bartlett, Hyun-Soo Cho, Katsuhiko S. Murakami Nov 2020

Direct Binding Of Tfeα Opens Dna Binding Cleft Of Rna Polymeras, Sung-Hoon Jun, Jaekyung Hyun, Hoyoung Kim, Michael S. Bartlett, Hyun-Soo Cho, Katsuhiko S. Murakami

Biology Faculty Publications and Presentations

Opening of the DNA binding cleft of cellular RNA polymerase (RNAP) is necessary for transcription initiation but the underlying molecular mechanism is not known. Here, we report on the cryo-electron microscopy structures of the RNAP, RNAP-TFEα binary, and RNAPTFEα-promoter DNA ternary complexes from archaea, Thermococcus kodakarensis (Tko). The structures reveal that TFEα bridges the RNAP clamp and stalk domains to open the DNA binding cleft. Positioning of promoter DNA into the cleft closes it while maintaining the TFEα interactions with the RNAP mobile modules. The structures and photo-crosslinking results also suggest that the conserved aromatic residue in the extended winged-helix …


Endothelial Cell Contributions To Covid-19, Alexandra E. Oxford, Fabio Halla, Evan B. Robertson, Brad E. Morrison Oct 2020

Endothelial Cell Contributions To Covid-19, Alexandra E. Oxford, Fabio Halla, Evan B. Robertson, Brad E. Morrison

Biology Faculty Publications and Presentations

Understanding of the clinical, histological and molecular features of the novel coronavirus 2019 (Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)) has remained elusive. Coronavirus disease 2019 (COVID-19) caused by this virus has unusual clinical presentation with regard to other related coronaviruses. Recent reports suggest that SARS-CoV-2, unlike other related viruses, infects and replicates within endothelial cells, which may explain a significant portion of the observed clinical pathology. Likewise, mounting evidence associates vascular and endothelial cell dysfunction with increased mortality. This review focuses on understanding how endothelial cell pathology is caused by SARS-CoV-2 at the molecular and cellular levels and how …


Investigation Of An Elevational Gradient Reveals Strong Differences Between Bacterial And Eukaryotic Communities Coinhabiting Nepenthes Phytotelmata, Kadeem J. Gilbert, Leonora S. Bittleston, Mark Arcebal K. Naive, Anthony E. Kiszewski, Perry Archival C. Buenavente, David J. Lohman, Naomi E. Pierce Aug 2020

Investigation Of An Elevational Gradient Reveals Strong Differences Between Bacterial And Eukaryotic Communities Coinhabiting Nepenthes Phytotelmata, Kadeem J. Gilbert, Leonora S. Bittleston, Mark Arcebal K. Naive, Anthony E. Kiszewski, Perry Archival C. Buenavente, David J. Lohman, Naomi E. Pierce

Biology Faculty Publications and Presentations

Elevation is an important determinant of ecological community composition. It integrates several abiotic features and leads to strong, repeatable patterns of community structure, including changes in the abundance and richness of numerous taxa. However, the influence of elevational gradients on microbes is understudied relative to plants and animals. To compare the influence of elevation on multiple taxa simultaneously, we sampled phytotelm communities within a tropical pitcher plant (Nepenthes mindanaoensis) along a gradient from 400 to 1200 m a.s.l. We use a combination of metabarcoding and physical counts to assess diversity and richness of bacteria, micro-eukaryotes, and arthropods, and …


Host-Dependent Differences In Replication Strategy Of The Sulfolobus Spindle-Shaped Virus Strain Ssv9 (A.K.A., Ssvk1): Infection Profiles In Hosts Of The Family Sulfolobaceae, Ruben M. Ceballos, Coyne Gareth Drummond, Carson Len Stacy, Elizabeth Padillo-Crespo, Kenneth M. Stedman Jul 2020

Host-Dependent Differences In Replication Strategy Of The Sulfolobus Spindle-Shaped Virus Strain Ssv9 (A.K.A., Ssvk1): Infection Profiles In Hosts Of The Family Sulfolobaceae, Ruben M. Ceballos, Coyne Gareth Drummond, Carson Len Stacy, Elizabeth Padillo-Crespo, Kenneth M. Stedman

Biology Faculty Publications and Presentations

The Sulfolobus Spindle-shaped Virus (SSV) system has become a model for studying thermophilic virus biology, including archaeal host-virus interactions and biogeography. Several factors make the SSV system amenable to studying archaeal genetic mechanisms (e.g., CRISPRs) as well as virus-host interactions in high temperature acidic environments. Previously, we reported that SSVs exhibited differential infectivity on allopatric vs. sympatric hosts. We also noticed a wide host range for virus strain SSV9 (a.k.a., SSVK1). For decades, SSVs have been described as “non-lytic” double-stranded DNA viruses that infect species of the genus Sulfolobus and release virions via budding rather than host lysis. In this …


Context-Dependent Dynamics Lead To The Assembly Of Functionally Distinct Microbial Communities, Leonora S. Bittleston, Matti Gralka, Gabriel E. Levanthal, Itzhak Mizrahi, Otto X. Cordero Mar 2020

Context-Dependent Dynamics Lead To The Assembly Of Functionally Distinct Microbial Communities, Leonora S. Bittleston, Matti Gralka, Gabriel E. Levanthal, Itzhak Mizrahi, Otto X. Cordero

Biology Faculty Publications and Presentations

Niche construction through interspecific interactions can condition future community states on past ones. However, the extent to which such history dependency can steer communities towards functionally different states remains a subject of active debate. Using bacterial communities collected from wild pitchers of the carnivorous pitcher plant, Sarracenia purpurea, we test the effects of history on composition and function across communities assembled in synthetic pitcher plant microcosms. We find that the diversity of assembled communities is determined by the diversity of the system at early, pre-assembly stages. Species composition is also contingent on early community states, not only because of …


Unveiling Crucivirus Diversity By Mining Metagenomic Data, Ignacio De La Higuera, George Kasun, Ellis L. Torrance, Alyssa A. Pratt, Amberlee Maluenda, Jonathan Colombet, Maxime Bisseux, Viviane Ravet, Anisha Dayaram, Daisy Stainton, Simona Kraberger, Peyman Zawar-Reza, Sharyn Goldstien, James V. Briskie, Robyn White, Helen Taylor, Christopher Gomez, David G. Ainley, Jon S. Harding, Rafaela S. Fontenele, Joshua Schreck, Simone Ribeiro, Stephen A. Oswald, Jennifer M. Arnold, François Enault, Arvind Varsani, Kenneth M. Stedman Jan 2020

Unveiling Crucivirus Diversity By Mining Metagenomic Data, Ignacio De La Higuera, George Kasun, Ellis L. Torrance, Alyssa A. Pratt, Amberlee Maluenda, Jonathan Colombet, Maxime Bisseux, Viviane Ravet, Anisha Dayaram, Daisy Stainton, Simona Kraberger, Peyman Zawar-Reza, Sharyn Goldstien, James V. Briskie, Robyn White, Helen Taylor, Christopher Gomez, David G. Ainley, Jon S. Harding, Rafaela S. Fontenele, Joshua Schreck, Simone Ribeiro, Stephen A. Oswald, Jennifer M. Arnold, François Enault, Arvind Varsani, Kenneth M. Stedman

Biology Faculty Publications and Presentations

The discovery of cruciviruses revealed the most explicit example of a common protein homologue between DNA and RNA viruses to date. Cruciviruses are a novel group of circular Rep-encoding single-stranded DNA (ssDNA) (CRESSDNA) viruses that encode capsid proteins that are most closely related to those encoded by RNA viruses in the family Tombusviridae. The apparent chimeric nature of the two core proteins encoded by crucivirus genomes suggests horizontal gene transfer of capsid genes between DNA and RNA viruses. Here, we identified and characterized 451 new crucivirus genomes and 10 capsid-encoding circular genetic elements through de novo assembly and mining of …