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Full-Text Articles in Medical Microbiology
Structural And Functional Diversity Of Type Iv Secretion Systems, Tiago R D Costa, Jonasz B Patkowski, Kévin Macé, Peter J Christie, Gabriel Waksman
Structural And Functional Diversity Of Type Iv Secretion Systems, Tiago R D Costa, Jonasz B Patkowski, Kévin Macé, Peter J Christie, Gabriel Waksman
Student and Faculty Publications
Considerable progress has been made in recent years in the structural and molecular biology of type IV secretion systems in Gram-negative bacteria. The latest advances have substantially improved our understanding of the mechanisms underlying the recruitment and delivery of DNA and protein substrates to the extracellular environment or target cells. In this Review, we aim to summarize these exciting structural and molecular biology findings and to discuss their functional implications for substrate recognition, recruitment and translocation, as well as the biogenesis of extracellular pili. We also describe adaptations necessary for deploying a breadth of processes, such as bacterial survival, host–pathogen …
Chimeric Systems Composed Of Swapped Tra Subunits Between Distantly-Related F Plasmids Reveal Striking Plasticity Among Type Iv Secretion Machines, Kouhei Kishida, Yang Grace Li, Natsumi Ogawa-Kishida, Pratick Khara, Abu Amar M Al Mamun, Rachel E Bosserman, Peter J Christie
Chimeric Systems Composed Of Swapped Tra Subunits Between Distantly-Related F Plasmids Reveal Striking Plasticity Among Type Iv Secretion Machines, Kouhei Kishida, Yang Grace Li, Natsumi Ogawa-Kishida, Pratick Khara, Abu Amar M Al Mamun, Rachel E Bosserman, Peter J Christie
Student and Faculty Publications
Bacterial type IV secretion systems (T4SSs) are a versatile family of macromolecular translocators, collectively able to recruit diverse DNA and protein substrates and deliver them to a wide range of cell types. Presently, there is little understanding of how T4SSs recognize substrate repertoires and form productive contacts with specific target cells. Although T4SSs are composed of a number of conserved subunits and adopt certain conserved structural features, they also display considerable compositional and structural diversity. Here, we explored the structural bases underlying the functional versatility of T4SSs through systematic deletion and subunit swapping between two conjugation systems encoded by the …
Illuminating Type Iv Secretion-Mediated Dna Trafficking Through Long Filaments, Peter J Christie
Illuminating Type Iv Secretion-Mediated Dna Trafficking Through Long Filaments, Peter J Christie
Student and Faculty Publications
No abstract provided.
The At-Hook Is An Evolutionarily Conserved Auto-Regulatory Domain Of Swi/Snf Required For Cell Lineage Priming, Dhurjhoti Saha, Solomon Hailu, Arjan Hada, Junwoo Lee, Jie Luo, Jeff A Ranish, Yuan-Chi Lin, Kyle Feola, Jim Persinger, Abhinav Jain, Bin Liu, Yue Lu, Payel Sen, Blaine Bartholomew
The At-Hook Is An Evolutionarily Conserved Auto-Regulatory Domain Of Swi/Snf Required For Cell Lineage Priming, Dhurjhoti Saha, Solomon Hailu, Arjan Hada, Junwoo Lee, Jie Luo, Jeff A Ranish, Yuan-Chi Lin, Kyle Feola, Jim Persinger, Abhinav Jain, Bin Liu, Yue Lu, Payel Sen, Blaine Bartholomew
Student and Faculty Publications
The SWI/SNF ATP-dependent chromatin remodeler is a master regulator of the epigenome, controlling pluripotency and differentiation. Towards the C-terminus of the catalytic subunit of SWI/SNF is a motif called the AT-hook that is evolutionary conserved. The AT-hook is present in many chromatin modifiers and generally thought to help anchor them to DNA. We observe however that the AT-hook regulates the intrinsic DNA-stimulated ATPase activity aside from promoting SWI/SNF recruitment to DNA or nucleosomes by increasing the reaction velocity a factor of 13 with no accompanying change in substrate affinity (K
Lipid Surfaces And Glutamate Anions Enhance Formation Of Dynamic Biomolecular Condensates Containing Bacterial Cell Division Protein Ftsz And Its Dna-Bound Regulator Slma, Gianfranco Paccione, Miguel Á Robles-Ramos, Carlos Alfonso, Marta Sobrinos-Sanguino, William Margolin, Silvia Zorrilla, Begoña Monterroso, Germán Rivas
Lipid Surfaces And Glutamate Anions Enhance Formation Of Dynamic Biomolecular Condensates Containing Bacterial Cell Division Protein Ftsz And Its Dna-Bound Regulator Slma, Gianfranco Paccione, Miguel Á Robles-Ramos, Carlos Alfonso, Marta Sobrinos-Sanguino, William Margolin, Silvia Zorrilla, Begoña Monterroso, Germán Rivas
Student and Faculty Publications
Dynamic biomolecular condensates formed by liquid-liquid phase separation can regulate the spatial and temporal organization of proteins, thus modulating their functional activity in cells. Previous studies showed that the cell division protein FtsZ from Escherichia coli formed dynamic phase-separated condensates with nucleoprotein complexes containing the FtsZ spatial regulator SlmA under crowding conditions, with potential implications for condensate-mediated spatiotemporal control of FtsZ activity in cell division. In the present study, we assessed formation of these condensates in the presence of lipid surfaces and glutamate ions to better approximate the E. coli intracellular environment. We found that potassium glutamate substantially promoted the …
Overlapping And Distinct Functions Of The Paralogous Pagr Regulators Of Bacillus Anthracis, Ileana D Corsi, Theresa M Koehler
Overlapping And Distinct Functions Of The Paralogous Pagr Regulators Of Bacillus Anthracis, Ileana D Corsi, Theresa M Koehler
Student and Faculty Publications
The Bacillus anthracis pagA gene, encoding the protective antigen component of anthrax toxin, is part of a bicistronic operon on pXO1 that codes for its own repressor, PagR1. In addition to the pagAR1 operon, PagR1 regulates sap and eag, two chromosome genes encoding components of the surface layer, a mounting structure for surface proteins involved in virulence. Genomic studies have revealed a PagR1 paralog, PagR2, encoded by a gene on pXO2. The amino acid sequences of the paralogues are 71% identical and show similarity to the ArsR family of transcription regulators. We determined that the expression of either rPagR1 …
Pcr-Based Assay Using Occult Blood Detection Cards For Detection Of Diarrheagenic Escherichia Coli In Specimens From Us Travelers To Mexico With Acute Diarrhea, Kevin A Grimes, Jamal A Mohamed, Herbert L Dupont, Ranjit S Padda, Zhi-Dong Jiang, Jose Flores, Jaime Belkind-Gerson, Francisco G Martinez-Sandoval, Pablo C Okhuysen
Pcr-Based Assay Using Occult Blood Detection Cards For Detection Of Diarrheagenic Escherichia Coli In Specimens From Us Travelers To Mexico With Acute Diarrhea, Kevin A Grimes, Jamal A Mohamed, Herbert L Dupont, Ranjit S Padda, Zhi-Dong Jiang, Jose Flores, Jaime Belkind-Gerson, Francisco G Martinez-Sandoval, Pablo C Okhuysen
Faculty and Staff Publications
Large field studies of travelers' diarrhea for multiple destinations are limited by the need to perform stool cultures on site in a timely manner. A method for the collection, transport, and storage of fecal specimens that does not require immediate processing and refrigeration and that is stable for months would be advantageous. This study was designed to determine if enterotoxigenic Escherichia coli (ETEC) and enteroaggregative E. coli (EAEC) DNA could be identified from cards that were processed for the evaluation of fecal occult blood. U.S. students traveling to Mexico during 2005 to 2007 were monitored for the occurrence of diarrheal …
Functional Taxonomy Of Bacterial Hyperstructures, Vic Norris, Tanneke Den Blaauwen, Armelle Cabin-Flaman, Roy H Doi, Rasika Harshey, Laurent Janniere, Alfonso Jimenez-Sanchez, Ding Jun Jin, Petra Anne Levin, Eugenia Mileykovskaya, Abraham Minsky, Milton Saier, Kirsten Skarstad
Functional Taxonomy Of Bacterial Hyperstructures, Vic Norris, Tanneke Den Blaauwen, Armelle Cabin-Flaman, Roy H Doi, Rasika Harshey, Laurent Janniere, Alfonso Jimenez-Sanchez, Ding Jun Jin, Petra Anne Levin, Eugenia Mileykovskaya, Abraham Minsky, Milton Saier, Kirsten Skarstad
Faculty and Staff Publications
The levels of organization that exist in bacteria extend from macromolecules to populations. Evidence that there is also a level of organization intermediate between the macromolecule and the bacterial cell is accumulating. This is the level of hyperstructures. Here, we review a variety of spatially extended structures, complexes, and assemblies that might be termed hyperstructures. These include ribosomal or "nucleolar" hyperstructures; transertion hyperstructures; putative phosphotransferase system and glycolytic hyperstructures; chemosignaling and flagellar hyperstructures; DNA repair hyperstructures; cytoskeletal hyperstructures based on EF-Tu, FtsZ, and MreB; and cell cycle hyperstructures responsible for DNA replication, sequestration of newly replicated origins, segregation, compaction, and …