Other Biochemistry, Biophysics, and Structural Biology Commons^™

Differences In Blood-Derived Francisella Tularensis Type B Strains From Clinical Cases Of Tularemia, Marilyn A. Larson, Baha Abdalhamid, Bhanwar Lal Puniya, Tomáš Helikar, David W. Kelley, Peter C. Iwen

Department of Biochemistry: Faculty Publications

Francisella tularensis can cause the zoonotic disease tularemia and is partitioned into subspecies due to differences in chromosomal organization and virulence. The subspecies holarctica (type B) is generally considered more clonal than the other subpopulations with moderate virulence compared to the hypervirulent A.I clade. We performed whole genome sequencing (WGS) on six type B strains isolated from the blood of patients with tularemia within a one-year period from the same United States region, to better understand the associated pathogenicity. The WGS data were compared to the prototype strain for this subspecies, specifically FSC200, which was isolated from a patient with …

Reactive Oxygen Species (Ros) Mediated Degradation Of Organophosphate T Pesticides By The Green Microalgae Coccomyxa Subellipsoidea☆, Timothy J Nicodemus, Concetta C. Dirusso, Mark A. Wilson, Paul N. Black

Department of Biochemistry: Faculty Publications

The aim of this study was to define the mechanism allowing the green alga Coccomyxa subellipsoidea to break down organophosphates from agricultural run-off. This study found that metabolically active cultures of the microalga C. subellipsoidea breakdown organophosphates (paraoxon, malathion and diazinon) with differing structural conformations in freshwater through a mechanism that requires the formation of reactive oxygen species (ROS) with little to no toxic effects on the algae. Under these conditions, organophosphate levels were reduced to 0.1 mg/mL or less over the 8–10 day experimental period. These findings demonstrate a biological- based system can be tailored for the remediation of …

Insights From The Inclusive Environments And Metrics In Biology Education And Research Network: Our Experience Organizing Inclusive Biology Education Research Events, Rebecca A. Campbell-Montalvo, Natalia Caporale, Gary S. Mcdowell, Candice Idlebird, Katie M. Wiens, Kimberly M. Jackson, Jana D. Marcette, Michael E. Moore

Department of Biochemistry: Faculty Publications

In contrast to efforts focusing on improving inclusion in STEM classrooms from kindergarten through un-dergraduate (K–16), efforts to improve inclusion in scientific meetings and conferences, important hubs of STEM culture, are more recent. Markers of inclusion that are sometimes overlooked at these events can include the composition of panels, how workshops are run, the affordability of conferences, and various other mechanisms that maintain pre-existing hierarchies and norms that limit the participation of early-career researchers and individuals of minoritized cultural, linguistic, and economic backgrounds. The Inclusive Environments and Metrics in Biology Education and Research (iEMBER) network coordinates efforts of researchers from …

Training Population Optimization For Genomic Selection In Miscanthus, Marcus O. Olatoye, Lindsay V. Clark, Nicholas R. Labonte, Hongxu Dong, Maria S. Dwiyanti, Kossonou G. Anzoua, Joe E. Brummer, Bimal K. Ghimire, Elena Dzyubenko, Nikolay Dzyubenko, Larisa Bagmet, Andrey Sabitov, Pavel Chebukin, Katarzyna Głowacka, Kweon Heo, Xiaoli Jin, Hironori Nagano, Junhua Peng, Chang Y. Yu, Ji H. Yoo, Hua Zhao, Stephen P. Long, Toshihiko Yamada, Erik J. Sacks, Alexander E. Lipka

Department of Biochemistry: Faculty Publications

Miscanthus is a perennial grass with potential for lignocellulosic ethanol production. To ensure its utility for this purpose, breeding efforts should focus on increasing genetic diversity of the nothospecies Miscanthus x giganteus (M·g) beyond the single clone used in many programs. Germplasm from the corresponding parental speciesM. sinensis (Msi) and M. sacchariflorus (Msa) could theoretically be used as training sets for genomic prediction of M·g clones with optimal genomic estimated breeding values for biofuel traits. To this end, we first showed that subpopulation structure makes a substantial contribution to the genomic selection (GS) prediction accuracies within a 538-member diversity panel …

Factors Influencing Huntingtin Aggregation At Surfaces: Implications For Huntington’S Disease, Sharon E. Groover

Graduate Theses, Dissertations, and Problem Reports

Huntington’s Disease (HD) is a genetic, neurodegenerative disease characterized by an abnormal polyglutamine (polyQ) expansion in the first exon of the huntingtin protein (htt). The polyQ domain facilitates aggregation and initiates the formation of a diverse collection of aggregate species, including fibrils, oligomers and annular aggregates. The first 17 amino acids of htt (Nt17) directly flank the polyQ domain and is a key factor in htt’s association to membranous structures. In addition to Nt17 being an amphipathic αhelix, it also promotes aggregation through self-association and contains numerous posttranslational modifications (PTMs) that can modulate toxicity and subcellular localization. For in depth …

Alanyl-Trna Synthetase Quality Control Prevents Global Dysregulation Of The Escherichia Coli Proteome, Paul Kelly, Nicholas Backes, Kyle Mohler, Christopher Buser, Arundhati Kavoor, Jesse Rinehart, Gregory Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Mechanisms have evolved to prevent errors in replication, transcription, and translation of genetic material, with translational errors occurring most frequently. Errors in protein synthesis can occur at two steps, during tRNA aminoacylation and ribosome decoding. Recent advances in protein mass spectrometry have indicated that previous reports of translational errors have potentially underestimated the frequency of these events, but also that the majority of translational errors occur during ribosomal decoding, suggesting that aminoacylation errors are evolutionarily less tolerated. Despite that interpretation, there is evidence that some aminoacylation errors may be regulated, and thus provide a benefit to the cell, while others …

Structural Basis Of Non-Canonical Transcriptional Regulation By The A-Bound Iron-Sulfur Protein Whib1 In M. Tuberculosis, Tao Wan, Shanren Li, Daisy Guiza Beltran, Andrew Schacht, Lu Zhang, Donald F. Becker, Limei Zhang

Department of Biochemistry: Faculty Publications

WhiB1 is amonomeric iron–sulfur cluster-containing transcription factor in the WhiB-like family that is widely distributed in actinobacteria including the notoriously persistent pathogen Mycobacterium tuberculosis (M. tuberculosis). WhiB1 plays multiple roles in regulating cell growth and responding to nitric oxide stress inM. tuberculosis, but its underlying mechanism is unclear. Here we report a 1.85 A° -resolution crystal structure of the [4Fe–4S] cluster-bound (holo- )WhiB1 in complex with the C-terminal domain of the 70-family primary sigma factor A of M. tuberculosis containing the conserved region 4 (A 4). Region 4 of the 70-family primary sigma factors is commonly used by transcription factors …

High-Throughput Nano-Scale Characterization Of Membrane Proteins Using Fluorescence-Detection Size-Exclusion Chromatography, Alex J. Vecchio, Robert M. Stroud

Department of Biochemistry: Faculty Publications

Structural biology has revealed predicting heterologous expression levels, homogeneity, and stability of a protein from its primary structure are exceedingly difficult. Membrane proteins, in particular, present numerous challenges that make obtaining milligram quantities of quality samples problematic. For structural and functional investigation of these molecules, however, this is what is required. Fluorescence size-exclusion chromatography (F-SEC), a technique where a protein of biological interest is fused to green fluorescent protein (GFP) and monitored, circumvents many bottlenecks inherent to membrane protein structural biology. In vivo expression yields, as well as in vitro homogeneity and stability, can be rapidly evaluated utilizing nanogram quantities …

Effects Of The Dihydrouracil Lesion On Dna Using 1h/31p 1d And 2d Solution Nmr, Benjamin M. Boyd

MSU Graduate Theses

The effects of the dihydrouracil lesion in DNA were studied using two dimensional NMR spectroscopy. The sequence used was based off of the Drew-Dickerson Dodecamer, with the cytosine in the three position replaced by a dihydrouracil. All of the nonexchangeable proton chemical shifts, with the exception of the H2, H5’, and H5’’, of the lesioned DNA were identified using NOESY spectra and then compared to the chemical shift values of the Drew Dickerson Dodecamer. The largest differences in chemical shifts were observed in the nucleotides neighboring the lesion, both within the strand and on the opposite strand. The imino exchangeable …

High Concentrations Of Trimethylamines In Slime Glands Inhibit Skein Unraveling In Pacific Hagfish, Gaurav Jain, Marie Starksen, Kashika Singh, Christopher Hoang, Paul Yancey, Charlene Mccord, Douglas S. Fudge

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Hagfish defend themselves from fish predators by producing large volumes of gill-clogging slime when they are attacked. The slime consists of seawater and two major components that are ejected from the slime glands: mucus and threads. The threads are produced within specialized cells and packaged into intricately coiled bundles called skeins. Skeins are kept from unraveling via a protein adhesive that dissolves when the skeins are ejected from the slime glands. Previous work revealed that hagfish slime glands have high concentrations of methylamines including trimethylamine N-oxide (TMAO), trimethylglycine (betaine) and dimethylglycine (DMG); however, the function of these compounds in the …

Comparison Of Montage With Conventional Stereoscopic Seven‑Field Photographs For Assessment Of Etdrs Diabetic Retinopathy Severity, Nam V. Nguyen, Erin M. Vigil, Muhammad Hassan, Muhammad S. Halim, Sean C. Baluyot, Hugo A. Guzman, Rubbia Afridi, Diana V. Do, Yasir J. Sepah

Department of Biochemistry: Faculty Publications

Background: The ETDRS stereoscopic seven-field (7F) has been a standard imaging and grading protocol for assessment of diabetic retinopathy (DR) severity score in many clinical trials. To the best of our knowledge, the comparison between montage and stereoscopic 7F has not been reported in the literature. Therefore, the main purpose of this study is to compare agreement between montage and stereoscopic seven-field (7F) photographs in the assessment of DR severity.

Methods: Stereoscopic 7F photographs were captured from subjects with DR. Montages of monoscopic 7F images were created using Adobe Photoshop CS6 Extended©. The best quality image of each stereo pair …

Remodeling Of Chlamydomonas Metabolism Using Synthetic Inducers Results In Lipid Storage During Growth, Nishikant Wase, Boqiang Tu, Girish Kumar Rasineni, Ronald Cerny, Ryan Grove, Jiri Adamec, Paul N. Black, Concetta Dirusso

Department of Biochemistry: Faculty Publications

Microalgae accumulate lipids during stress such as that of nutrient deprivation, concomitant with cessation of growth and depletion of chloroplasts. By contrast, certain small chemical compounds selected by high-throughput screening in Chlamydomonas reinhardtii can induce lipid accumulation during growth, maintaining biomass. Comprehensive pathway analyses using proteomics, transcriptomics, and metabolomics data were acquired from Chlamydomonas cells grown in the presence of one of two structurally distinct lipid activators. WD10784 stimulates both starch and lipid accumulation, whereas WD30030-treated cells accumulate only lipids. The differences in starch accumulation are largely due to differential effects of the two compounds on substrate levels that feed …

Protein Detection And Structural Characterization By Mass Spectrometry Using Supramolecular Assemblies And Small Molecules, Bo Zhao

Doctoral Dissertations

Mass spectrometry (MS) has played an increasingly prominent role in proteomics and structure biology because it shows superior capabilities in identification, quantification and structural characterization of proteins. To realize its full potential in protein analysis, significant progress has been made in developing innovative techniques and reagents that can couple to MS detection. This dissertation demonstrates the use of polymeric supramolecular assemblies for enhanced protein detection in complex biological mixtures by MS. An amphiphilic random co-polymer scaffold is developed to form functional supramolecular assemblies for protein/ peptide enrichment. The influences of charge density and functional group pK_a on host-guest interactions …

The Fitness Landscape Of The African Salmonella Typhimurium St313 Strain D23580 Reveals Unique Properties Of The Pbt1 Plasmid, Rocío Canals, Roy R. Chaudhuri, Rebecca E. Steiner, Siân V. Owen, Natalia Quinones-Olvera, Melita A. Gordon, Michael Baym, Michael Ibba, Jay C. D. Hinton

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have used a transposon insertion sequencing (TIS) approach to establish the fitness landscape of the African Salmonella enterica serovar Typhimurium ST313 strain D23580, to complement our previous comparative genomic and functional transcriptomic studies. We used a genome-wide transposon library with insertions every 10 nucleotides to identify genes required for survival and growth in vitro and during infection of murine macrophages. The analysis revealed genomic regions important for fitness under two in vitro growth conditions. Overall, 724 coding genes were required for optimal growth in LB medium, and 851 coding genes were required for growth in SPI-2-inducing minimal medium. These …

Dynamic Regulation Of G-Protein Signaling, William C. Simke

Electronic Theses and Dissertations

G protein-coupled receptors (GPCRs) are involved in numerous signaling processes ranging from neuronal growth to immune cells tracking invaders. GPCR signaling plays a role in many human diseases and thus GPCRs are important drug targets. Yeast respond to mating pheromone using a GPCR signaling system homologous to those used in humans to polarize their cytoskeleton toward the pheromone source. This is accomplished by initializing a MAPK signaling cascade to arrest the cells in mitosis and upregulate expression of chemotropic proteins. Pathway desensitization is accomplished by the Regulator of G-protein Signaling (RGS). RGS abrogates signaling by binding to the active GPCR, …

Microvascular Stenosis In Critical Limb Ischemia: Role Of Partial Endothelial To Mesenchymal Transition, Jacqueline M. Chevalier

Electronic Thesis and Dissertation Repository

Critical limb ischemia (CLI) is a widespread and debilitating manifestation of atherosclerosis. Unfortunately, revascularization strategies are often precluded or unsuccessful, resulting in amputation. A major reason for treatment failure is likely co-existing abnormalities in ­­the microvasculature. However, the specific microvascular defects present in end-stage PAD in humans remain unknown.

The purpose of this study was to delineate abnormalities in the microvascular wall in the critically ischemic skeletal muscle of patients with CLI.

To elucidate the microvascular landscape in CLI, we studied human tibialis anterior and gastrocnemius muscles harvested from below-knee amputations of 10 individuals with CLI. Control muscles are from …

Translational Control Of Antibiotic Resistance, Anne Witzky, Rodney Tollerson Ii, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Many antibiotics available in the clinic today directly inhibit bacterial translation. Despite the past success of such drugs, their efficacy is diminishing with the spread of antibiotic resistance. Through the use of ribosomal modifications, ribosomal protection proteins, translation elongation factors and mistranslation, many pathogens are able to establish resistance to common therapeutics. However, current efforts in drug discovery are focused on overcoming these obstacles through the modification or discovery of new treatment options. Here, we provide an overview for common mechanisms of resistance to translation-targeting drugs and summarize several important breakthroughs in recent drug development.

Some Of The Most Interesting Casp11 Targets Through The Eyes Of Their Authors, Andriy Kryshtafovych, John Moult, Arnaud Basle, Alex Burgin, Timonthy K. Craig, Robert A. Edwards, Deborah Fass, Marcus D. Hartmann, Mateusz Korycinski, Richard J. Lewis, Donald Lorimer, Andrei N. Lupas, Janet Newman, Thomas S. Peat, Kurt H. Piepenbrink, Janani Prahlad, Mark J. Van Raaij, Forest Rohwer, Anca M. Segall, Victor Seguritan, Eric J. Sundberg, Abhimanyu K. Singh, Mark A. Wilson, Torsten Schwede

Kurt Piepenbrink

The Critical Assessment of protein Structure Prediction (CASP) experiment would not have been possible without the prediction targets provided by the experimental structural biology community. In this article, selected crystallographers providing targets for the CASP11 experiment discuss the functional and biological significance of the target proteins, highlight their most interesting structural features, and assess whether these features were correctly reproduced in the predictions submitted to CASP11.

Dna Uptake By Type Iv Filaments, Kurt H. Piepenbrink

Kurt Piepenbrink

Bacterial uptake of DNA through type IV filaments is an essential component of natural competence in numerous gram-positive and gram-negative species. Recent advances in the field have broadened our understanding of the structures used to take up extracellular DNA. Here, we review seminal experiments in the literature describing DNA binding by type IV pili, competence pili and the flp pili of Micrococcus luteus; collectively referred to here as type IV filaments. We compare the current state of the field on mechanisms of DNA uptake for these three appendage systems and describe the current mechanistic understanding of both DNA-binding and …

Role Of The Drosophila Beaf Protein In Chromatin Domain Insulator And Promoter Function, Mukesh Maharjan

LSU Doctoral Dissertations

Proper folding of eukaryotic genomes is required to allow correct interactions between different parts of chromosomes. Precise and timely interactions among different parts of a chromosome allow proper functioning inside a nucleus, including gene regulation, DNA replication and DNA repair. Eukaryotic regulatory elements that facilitate folding and interactions include enhancers, promoters and insulator elements. Insulator elements and their binding proteins play an important role in regulating correct chromatin structure and function. The Drosophila melanogaster special chromatin structure (scs’) is one such insulator. The Boundary Element Associated Factor (BEAF) binds to scs’. BEAF is a 32 kDa protein that has two …