Medicine and Health Sciences Commons^™

Acquisition Of Functions On The Outer Capsid Surface During Evolution Of Double-Stranded Rna Fungal Viruses, Carlos P. Mata, Daniel Luque, Josué Gómez-Blanco, Javier M. Rodríguez, José M. González, Nobuhiro Suzuki, Said A. Ghabrial, José L. Carrascosa, Benes L. Trus, José R. Castón

Plant Pathology Faculty Publications

Unlike their counterparts in bacterial and higher eukaryotic hosts, most fungal viruses are transmitted intracellularly and lack an extracellular phase. Here we determined the cryo-EM structure at 3.7 Å resolution of Rosellinia necatrix quadrivirus 1 (RnQV1), a fungal double-stranded (ds)RNA virus. RnQV1, the type species of the family Quadriviridae, has a multipartite genome consisting of four monocistronic segments. Whereas most dsRNA virus capsids are based on dimers of a single protein, the ~450-Å-diameter, T = 1 RnQV1 capsid is built of P2 and P4 protein heterodimers, each with more than 1000 residues. Despite a lack of sequence similarity between …

Genetic Signatures For Helicobacter Pylori Strains Of West African Origin, Kennady K. Bullock, Carrie L. Shaffer, Andrew W. Brooks, Ousman Secka, Mark H. Forsyth, Mark S. Mcclain, Timothy L. Cover

Veterinary Science Faculty Publications

Helicobacter pylori is a genetically diverse bacterial species that colonizes the stomach in about half of the human population. Most persons colonized by H. pylori remain asymptomatic, but the presence of this organism is a risk factor for gastric cancer. Multiple populations and subpopulations of H. pylori with distinct geographic distributions are recognized. Genetic differences among these populations might be a factor underlying geographic variation in gastric cancer incidence. Relatively little is known about the genomic features of African H. pylori strains compared to other populations of strains. In this study, we first analyzed the genomes of …

Allelic Variation In Cxcl16 Determines Cd3+ T Lymphocyte Susceptibility To Equine Arteritis Virus Infection And Establishment Of Long-Term Carrier State In The Stallion, Sanjay Sarkar, Ernest Bailey, Yun Young Go, R. Frank Cook, Ted Kalbfleisch, John E. Eberth, R. Lakshman Chelvarajan, Kathleen M. Shuck, Sergey Artiushin, Peter J. Timoney, Udeni B. R. Balasuriya

Maxwell H. Gluck Equine Research Center Faculty Publications

Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory, systemic, and reproductive disease of horses and other equid species. Following natural infection, 10–70% of the infected stallions can become persistently infected and continue to shed EAV in their semen for periods ranging from several months to life. Recently, we reported that some stallions possess a subpopulation(s) of CD3⁺ T lymphocytes that are susceptible to in vitro EAV infection and that this phenotypic trait is associated with long-term carrier status following exposure to the virus. In contrast, stallions not possessing the CD3⁺ T …

Equine Arteritis Virus Uses Equine Cxcl16 As An Entry Receptor, Sanjay Sarkar, Lakshman Chelvarajan, Yun Young Go, Frank Cook, Sergey Artiushin, Shankar Mondal, Kelsi Anderson, John E. Eberth, Peter J. Timoney, Theodore S. Kalbfleisch, Ernest F. Bailey, Udeni B. R. Balasuriya

Veterinary Science Faculty Publications

Previous studies in our laboratory have identified equine CXCL16 (EqCXCL16) to be a candidate molecule and possible cell entry receptor for equine arteritis virus (EAV). In horses, the CXCL16 gene is located on equine chromosome 11 (ECA11) and encodes a glycosylated, type I transmembrane protein with 247 amino acids. Stable transfection of HEK-293T cells with plasmid DNA carrying EqCXCL16 (HEK-EqCXCL16 cells) increased the proportion of the cell population permissive to EAV infection from < 3% to almost 100%. The increase in permissiveness was blocked either by transfection of HEK-EqCXCL16 cells with small interfering RNAs (siRNAs) directed against EqCXCL16 or by pretreatment with guinea pig polyclonal antibody against EqCXCL16 protein (Gp anti-EqCXCL16 pAb). Furthermore, using a virus overlay protein-binding assay (VOPBA) in combination with far-Western blotting, gradient-purified EAV particles were shown to bind directly to the EqCXCL16 protein in vitro. The binding of biotinylated virulent EAV strain Bucyrus at 4°C was significantly higher in HEK-EqCXCL16 cells than nontransfected HEK-293T cells. Finally, the results demonstrated …

Structures Of Eccb1 And Eccd1 From The Core Complex Of The Mycobacterial Esx-1 Type Vii Secretion System, Jonathan Mark Wagner, Sum Chan, Timothy J. Evans, Sara Kahng, Jennifer Kim, Mark A. Arbing, David Eisenberg, Konstantin V. Korotkov

Molecular and Cellular Biochemistry Faculty Publications

Background: The ESX-1 type VII secretion system is an important determinant of virulence in pathogenic mycobacteria, including Mycobacterium tuberculosis. This complicated molecular machine secretes folded proteins through the mycobacterial cell envelope to subvert the host immune response. Despite its important role in disease very little is known about the molecular architecture of the ESX-1 secretion system.

Results: This study characterizes the structures of the soluble domains of two conserved core ESX-1 components – EccB₁ and EccD₁. The periplasmic domain of EccB₁ consists of 4 repeat domains and a central domain, which together form a quasi …

Bpab, A Novel Protein Encoded By The Lyme Disease Spirochete's Cp32 Prophages, Binds To Erp Operator 2 Dna, Logan H. Burns, Claire A. Adams, Sean P. Riley, Brandon L. Jutras, Amy Bowman, Alicia M. Chenail, Anne E. Cooley, Laura A. Haselhorst, Alisha M. Moore, Kelly Babb, Michael G. Fried, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Borrelia burgdorferi produces Erp outer surface proteins throughout mammalian infection, but represses their synthesis during colonization of vector ticks. A DNA region 5′ of the start of erp transcription, Operator 2, was previously shown to be essential for regulation of expression. We now report identification and characterization of a novel erp Operator 2-binding protein, which we named BpaB. erp operons are located on episomal cp32 prophages, and a single bacterium may contain as many as 10 different cp32s. Each cp32 family member encodes a unique BpaB protein, yet the three tested cp32-encoded BpaB alleles all bound to the same DNA …

Dna-Binding By Haemophilus Influenzae And Escherichia Coli Ybab, Members Of A Widely-Distributed Bacterial Protein Family, Anne E. Cooley, Sean P. Riley, Keith Kral, M. Clarke Miller, Edward Demoll, Michael G. Fried, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

BACKGROUND: Genes orthologous to the ybaB loci of Escherichia coli and Haemophilus influenzae are widely distributed among eubacteria. Several years ago, the three-dimensional structures of the YbaB orthologs of both E. coli and H. influenzae were determined, revealing a novel "tweezer"-like structure. However, a function for YbaB had remained elusive, with an early study of the H. influenzae ortholog failing to detect DNA-binding activity. Our group recently determined that the Borrelia burgdorferi YbaB ortholog, EbfC, is a DNA-binding protein. To reconcile those results, we assessed the abilities of both the H. influenzae and E. coli YbaB proteins to bind DNA …

Borrelia Burgdorferi Ebfc Defines A Newly-Identified, Widespread Family Of Bacterial Dna-Binding Proteins, Sean P. Riley, Tomasz Bykowski, Anne E. Cooley, Logan H. Burns, Kelly Babb, Catherine A. Brissette, Amy Bowman, Matthew L. Rotondi, M. Clarke Miller, Edward Demoll, Kap Lim, Michael G. Fried, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Lyme disease spirochete, Borrelia burgdorferi, encodes a novel type of DNA-binding protein named EbfC. Orthologs of EbfC are encoded by a wide range of bacterial species, so characterization of the borrelial protein has implications that span the eubacterial kingdom. The present work defines the DNA sequence required for high-affinity binding by EbfC to be the 4 bp broken palindrome GTnAC, where ‘n’ can be any nucleotide. Two high-affinity EbfC-binding sites are located immediately 5′ of B. burgdorferi erp transcriptional promoters, and binding of EbfC was found to alter the conformation of erp promoter DNA. Consensus EbfC-binding …

Leptospira Interrogans Endostatin-Like Outer Membrane Proteins Bind Host Fibronectin, Laminin And Regulators Of Complement, Brian Stevenson, Henry A. Choy, Marija Pinne, Matthew L. Rotondi, M. Clarke Miller, Edward Demoll, Peter Kraiczy, Anne E. Cooley, Trevor P. Creamer, Marc A. Suchard, Catherine A. Brissette, Ashutosh Verma, David A. Haake

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The pathogenic spirochete Leptospira interrogans disseminates throughout its hosts via the bloodstream, then invades and colonizes a variety of host tissues. Infectious leptospires are resistant to killing by their hosts' alternative pathway of complement-mediated killing, and interact with various host extracellular matrix (ECM) components. The LenA outer surface protein (formerly called LfhA and Lsa24) was previously shown to bind the host ECM component laminin and the complement regulators factor H and factor H-related protein-1. We now demonstrate that infectious L. interrogans contain five additional paralogs of lenA, which we designated lenB, lenC, lenD, lenE and lenF …

The Toxoplasma Gondii Protein Rop2 Mediates Host Organelle Association With The Parasitophorous Vacuole Membrane, Anthony P. Sinai, Keith A. Joiner

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Toxoplasma gondii replicates within a specialized vacuole surrounded by the parasitophorous vacuole membrane (PVM). The PVM forms intimate interactions with host mitochondria and endoplasmic reticulum (ER) in a process termed PVM–organelle association. In this study we identify a likely mediator of this process, the parasite protein ROP2. ROP2, which is localized to the PVM, is secreted from anterior organelles termed rhoptries during parasite invasion into host cells. The NH₂-terminal domain of ROP2 (ROP2hc) within the PVM is exposed to the host cell cytosol, and has characteristics of a mitochondrial targeting signal. In in vitro assays, ROP2hc is …