Structural Biology Commons^™

Identification Of Regulatory Elements In The Untranslated Regions Of Streptolysin S Associated Gene A Messenger Rna From Group A Streptococcus, Cameron R. Carroll, Sara G. Nibar, Alexis S. Brown, Lauren R. Angello, Gabriela C. Pérez-Alvarado, Brian M. Lee

Journal of the South Carolina Academy of Science

Streptococcus pyogenes, also known as group A Streptococcus (GAS), is a human pathogen associated with a variety of diseases such as strep throat, scarlet fever, toxic shock syndrome, and necrotizing fasciitis. One of the virulence factors released by GAS during an invasive infection is a cytotoxic peptide, streptolysin S (SLS), which inhibits the immune response to necrotizing fasciitis. The streptolysin S associated gene A product, SagA, is modified to produce SLS. Thesag operon includes sagA and the genes required for enzyme-mediated post-translational modifications of SagA and the export of SLS. The sagA gene is contained within the pleiotropic …

Tail-Tape-Fused Virion And Non-Virion Rna Polymerases Of A Thermophilic Virus With An Extremely Long Tail, Anastasiia Chaban, Leonid Minakhin, Ekaterina Goldobina, Brain Bae, Yue Hao, Sergei Borukhov, Leena Putzeys, Maarten Boon, Florian Kabinger, Rob Lavigne, Kira S Makarova, Eugene V Koonin, Satish K Nair, Shunsuke Tagami, Konstantin Severinov, Maria L Sokolova

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Thermus thermophilus bacteriophage P23-45 encodes a giant 5,002-residue tail tape measure protein (TMP) that defines the length of its extraordinarily long tail. Here, we show that the N-terminal portion of P23-45 TMP is an unusual RNA polymerase (RNAP) homologous to cellular RNAPs. The TMP-fused virion RNAP transcribes pre-early phage genes, including a gene that encodes another, non-virion RNAP, that transcribes early and some middle phage genes. We report the crystal structures of both P23-45 RNAPs. The non-virion RNAP has a crab-claw-like architecture. By contrast, the virion RNAP adopts a unique flat structure without a clamp. Structure and sequence comparisons of …

Comparative Histological Study On The Algerian Thymus Ciliatus At Different Phenological Stages, Nina Sadou, Ratiba Seridi, Hamdi Bendif

Journal of Bioresource Management

The aim of the current study was to compare the histological observations of stems, leaves, and different secretory structures of Thymus ciliatus at three phenological stages. The anatomical observations of stems, leaves, and glandular trichomes were carried out by light microscopy. The results showed that phenological stages do not affect significantly the anatomical, whereas there was a significant increase in secretory trichomes. The glandular trichomes are distributed on the surface of the stems and the leaves. There are only two distinct types of secretory trichomes, Peltate consisting of a basal cell, a stalk cell, and an 8-celled head type, which …

On The Anti-Adipogenic Function Of Collagen Triple Helix Repeat-Containing Protein 1, Matthew E. Siviski

Electronic Theses and Dissertations

Adipogenesis is regulated by the coordinated activity of adipogenic transcription factors, including PPAR-gamma (PPARG) and C/EBP alpha (CEBPA). Thus, dysregulated adipogenesis predisposes adipose tissues to adipocyte hypertrophy and hyperplasia. We have previously reported that mice possessing a homozygous null gene mutation in collagen triple helix repeat-containing protein 1 (CTHRC1) have increased adiposity compared to wildtype mice, supporting the concept that CTHRC1 regulates body composition. Herein, we investigated the anti-adipogenic activity of CTHRC1. Using 3T3-L1 preadipocytes, we showed significantly reduced adipogenic differentiation in the presence of CTHRC1 commensurate to marked suppression of Cebpa and Pparg gene expression. In addition, CTHRC1 increased …

Using In Silico Tools To Analyze The 5ʹ Untranslated Regions Of The Alcohol Dehydrogenase Gene From Arabidopsis Thaliana And Omega Sequence, Reza Mohammadhassan, Tina Asadishad

Makara Journal of Science

The 5ʹ ends of protein-encoding genes contain 5ʹ untranslated regions (5ʹUTRs), which can effectively participate in regulating gene expression. The 5ʹUTRs of Arabidospis thaliana–derived alcohol dehydrogenase gene (AtADH) and omega (Ω) sequence from tobacco mosaic virus (TMV) are the most effective enhancers in biotechnology. In this study, bioinformatics techniques were employed to analyze the characteristics of the above sequences. After 5ʹUTR sequence collection, the inner ribosome entrance sites; small RNA (sRNA) target sequences; nucleotide contents; and upstream start and stop codons, ORFs, and coding DNA sequences of the Ω sequence and AtADH 5ʹUTR were identified. Moreover, the …

Analyzing Functional Interactions Of Designed Peptides By Nmr Spectroscopy, Wonsuk Choi

Pharmaceutical Sciences (MS) Theses

The development of small peptide-based therapeutics can be accelerated by the knowledge of relationships between the peptide structure and its functional interactions. Here, we report the analysis of two groups of synthetic peptides designed for two applications – broad bactericidal action and inhibition of protein-protein interactions in human cells. Novel amphiphilic peptides designed for antibacterial application incorporated arginine as cationic amino acids and non-natural amino acids that have aromatic side chains with similar hydrophobic properties as tryptophan. The interaction of lead cyclic peptides and their linear analogs with a phospholipid bilayer mimicking a bacterial membrane was studied using nuclear magnetic …

Flavonol Glucosylation: A Structural Investigation Of The Flavonol Specific 3-O Glucosyltransferase Cp3gt, Aaron S. Birchfield

Electronic Theses and Dissertations

Flavonoid glycosyltransferases (GTs), enzymes integral to plant ecological responses and human pharmacology, necessitate rigorous structural elucidation to decipher their mechanistic function and substrate specificity, particularly given their role in the biotransformation of diverse pharmacological agents and natural products. This investigation delved into a comprehensive exploration of the flavonol 3-O GT from Citrus paradisi (Cp3GT), scrutinizing the impact of a c-terminal c-myc/6x histidine tag on its enzymatic activity and substrate specificity, and successfully achieving its purification to apparent homogeneity. This established a strong foundation for potential future crystallographic and other structure/function analyses. Through the strategic implementation of site-directed mutagenesis, a thrombin …

The Identification Of Small Molecule Inhibitors To Candida Albicans Phosphatidylserine Synthase, Yue Zhou

Doctoral Dissertations

Candida albicans phosphatidylserine (PS) synthase, encoded by the CHO1 gene, has been identified as a potential drug target for new antifungals against systemic candidiasis due to its importance in virulence, absence in the host and conservation among fungal pathogens. This dissertation is focused on the identification of inhibitors for this membrane enzyme. Cho1 has two substrates: cytidyldiphosphate-diacylglycerol (CDP-DAG) and serine. Previous studies identified a conserved CDP-alcohol phosphotransferase (CAPT) binding motif present within Cho1, and here we revealed that mutations in all but one conserved amino acid within the CAPT motif resulted in decreased Cho1. For serine, we have predicted a …

Biochemical Analyses Of Udgx-A Crosslinking Uracil-Dna Glycosylase, Chuan Liang

All Dissertations

DNA base damage is common due to exposure to various endogenous and exogenous factors. To repair the base lesions, such as uracil from cytosine deamination, enzymes from the uracil-DNA glycosylase (UDG) superfamily are critical, which can recognize the damaged base and initiate the base excision repair (BER) pathway. There used to be six families of proteins identified in the UDG superfamily until a new member, UDGX, was found in Mycobacterium smegmatis, which is a unique DNA-crosslinking UDG. In this dissertation work, a series of biochemical analyses of the newly found UDGX are performed, including the analyses of structures, functions, …

Reactive Chemistries For Protein Labeling, Degradation, And Stimuli Responsive Delivery, Myrat Kurbanov

Doctoral Dissertations

Reactive chemistries for protein chemical modification play an instrumental role in chemical biology, proteomics, and therapeutics. Depending on the application, the selectivity of these modifications can range from precise modification of an amino acid sequence by genetic manipulation of protein expression machinery to a stochastic modification of lysine residues on the protein surface. Ligand-Directed (LD) chemistry is one of the few methods for targeted modification of endogenous proteins without genetic engineering. However, current LD strategies are limited by stringent amino acid selectivity. To bridge this gap, this thesis focuses on the development of highly reactive LD Triggerable Michael Acceptors (LD-TMAcs) …

Caulobacter Clpxp Adaptor Popa’S Domain Interactions In The Adaptor Hierarchy Of Ctra Degradation, Thomas P. Scudder

Masters Theses

The degradation and recycling of protein is a process essential for the maintenance and regulation of cellular function. More specifically, in Caulobacter crescentus, the ClpXP protease is responsible for driving progression through the cell cycle and protein quality control. This protease utilizes three known adaptors to selectively degrade proteins that initiate different stages of development. This thesis will elaborate on the specific binding interface on one of these adaptors, PopA, with another, RcdA, and focus in on specific residues on PopA and investigate their roles in adaptor binding and delivery of CtrA, the master regulator of Caulobacter. Finally, I …

Evaluating The Response Of Glycine Soja Accessions To Fungal Pathogen Macrophomina Phaseolina During Seedling Growth, Shirley Jacquet, Layla Rashad, Sonia Viera, Francisco Reta, Juan Reta

Biological Science Student Working Papers

Charcoal rot caused by the fungal pathogen Macrophomina phaseolina (Tassi) Goid is one of various devastating soybean (Glycine max (L.) Merr.) diseases, which can severely reduce crop yield. The investigation into the genetic potential for charcoal rot resistance of wild soybean (Glycine soja) accessions will enrich our understanding of the impact of soybean domestication on disease resistance; moreover, the identified charcoal rot-resistant lines can be used to improve soybean resistance to charcoal rot. The objective of this study was to evaluate the resistance of wild soybean accessions to M. phaseolina at the seedling stage and thereby select the disease-resistant lines. …

Langevin Dynamic Models For Smfret Dynamic Shift, David Frost, Keisha Cook Dr, Hugo Sanabria Dr

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Effects Of Growth Rate On Peptidoglycan Crosslink Density Of E. Coli Using Fluorescent Labeling, Morgan Olszewski

Harrisburg University Research Symposium: Highlighting Research, Innovation, & Creativity

Peptidoglycan (PG) is a polymer composed of polysaccharides and crosslinked peptide chains found in bacterial cell walls. It helps to protect the cell from environmental stress and maintain cell morphology throughout its life cycle and further generations. The PG is made up of two sugars, N-acetyl muramic acid (NAM) and N-acetyl glucosamine (NAG). NAM and NAG are connected by glycosidic linkages to form repeated chains. The chains are formed in layers, which are interconnected via a polypeptide stem linked by a peptide bridge. During cell growth, continuous turnover of existing PG occurs by severing existing crosslinks, inserting new PG into …

Predicted Structure And Analysis Of The Glycoprotein From Sars-Cov-2 Variants Of Interest, Boris Shabaltiy

Honors Theses

SARS-CoV-2 has had a devastating effect on the world, and while the public concern and severity of the diseased caused by it have decreased, it is still crucial to monitor the virus for mutations so we can rapidly identify new variants of concern, and then rapidly prepare new vaccines and treatments. The SARS-CoV-2 spike (S) protein from the first isolates of the virus (root variant) was structurally characterized in early 2021. The spike protein structure, designated 7CZW, was uploaded to RCSB Protein Data Bank (RCSB PDB). All subsequent mutations the S protein has accumulated are based on the amino acid …

Protein Stability In Solution And In The Gas Phase., Yousef Haidar

Electronic Thesis and Dissertation Repository

Electrospray Ionization mass spectrometry (ESI-MS) is widely used for probing proteins, yet many aspects of this technique remain elusive. Using MS, ion mobility spectrometry (IMS), and circular dichroism (CD) spectroscopy, this thesis sheds light on the stability differences of proteins in the gas phase and solution. After a general introduction (Chapter 1), Chapter 2 scrutinizes some aspects of native ESI. Our data highlight the significance of cone voltage in maintaining a native-like fold and show the advantage of using NH₄Ac in protein experiments. Chapter 3 focuses on hydrogen/deuterium exchange (HDX)-MS. Several studies have reported that D₂O …

Optimization And Application Of Graph Neural Networks, Shuo Zhang

Dissertations, Theses, and Capstone Projects

Graph Neural Networks (GNNs) are widely recognized for their potential in learning from graph-structured data and solving complex problems. However, optimal performance and applicability of GNNs have been an open-ended challenge. This dissertation presents a series of substantial advances addressing this problem. First, we investigate attention-based GNNs, revealing a critical shortcoming: their ignorance of cardinality information that impacts their discriminative power. To rectify this, we propose Cardinality Preserved Attention (CPA) models that can be applied to any attention-based GNNs, which exhibit a marked improvement in performance. Next, we introduce the Directional Node Pair (DNP) descriptor and the Robust Molecular Graph …

Characterization Of Pathological Tau Mutants, Charles J. Mcdonald

Dissertations, Theses, and Capstone Projects

Tau is a protein expressed exclusively in glia and neurons in the central nervous system and implicated in several neurogenerative diseases called “tauopathies”. Among all the tauopathies, one third is characterized by the presence of genetic mutations leading to the synthesis of tau proteins with single amino acid substitutions at specific locations and affecting protein function. While most of the initial studies have emphasize the functional role of tau as modulator of the axonal cytoskeleton, it has recently been well accepted that tau is also an intrinsically disordered protein that tends to form membraneless organelles called coacervates, due to a …

Exploring Topological Phonons In Different Length Scales: Microtubules And Acoustic Metamaterials, Ssu-Ying Chen

Dissertations

The topological concepts of electronic states have been extended to phononic systems, leading to the prediction of topological phonons in a variety of materials. These phonons play a crucial role in determining material properties such as thermal conductivity, thermoelectricity, superconductivity, and specific heat. The objective of this dissertation is to investigate the role of topological phonons at different length scales.

Firstly, the acoustic resonator properties of tubulin proteins, which form microtubules, will be explored The microtubule has been proposed as an analog of a topological phononic insulator due to its unique properties. One key characteristic of topological materials is the …

Nanodiscs: A Novel Approach To The Study Of The Methionine Abc Transporter System, Michael T. Winslow

Master's Theses

Membrane transporter proteins play the vital role of moving compounds in and out of the cell and are essential for all living organisms. ATP Binding Cassette (ABC) family transporters function both as importers and exporters in prokaryotes. MetNI is an E. coli Type I ABC transporter responsible for the uptake of methionine into the cytosol from the cell periplasmic space through the cell membrane to maintain intracellular methionine pools. ABC transporters, like other membrane proteins, are most often mechanistically and structurally studied in vitro, solubilized by detergents. However, detergent micelles may affect the conformational changes of membrane proteins relative to …

Identification Of A Small Regulatory Rna Usps Associated With The Universal Stress Protein In Lactobacillus Species, Zarah M. Fowler, Sasha S. Bronovitskiy, Finn K. Rose, Brian M. Lee

Journal of the South Carolina Academy of Science

The gut microbiome is a complex habitat with many bacterial species, each playing crucial roles in regulating various physiological processes in the body. As the use of probiotics to combat human disease continues to increase, it is important to understand the mechanisms by which probiotic bacteria regulate their interactions with other bacteria and their host. Our exploration of the physiological functions of probiotic bacteria hopes to elucidate the role of small regulatory RNA (sRNA) in regulating gene expression within the microbiome. The goal of this project was to characterize the structure and function of the sRNA, UspS, which is found …

New Dna Repair And Demethylation Functions In Uracil Dna Glycosylase Superfamily, Chenyan Chang

All Dissertations

Uracil-DNA glycosylase (UDG) superfamily, which consists of several groups of enzymes that recognize the damaged DNA bases and initiate the base excision repair (BER) pathway, is most important in dealing with DNA deamination and other base modifications. Thymine DNA glycosylase (TDG), which belongs to family 2 in the UDG superfamily, is able to specifically recognize and cleave the 5-methylcytosine (mC) oxidative derivatives including 5-formylcytosine (fC), 5-carboxylcytosine (caC), 5-hydromethyluracil (hmU) caused by active demethylation or DNA damage. My dissertation work is mainly focused on the fC and caC glycosylase activity within UDG superfamily. Chapter 1 is a general introduction to the …

Expression, Purification, And Characterization Of Fibroblast Growth Factor 19, Elizabeth Ford

Chemistry & Biochemistry Undergraduate Honors Theses

Fibroblast growth factors (FGFs) are a family of signaling proteins with diverse biological functions. Fibroblast growth factor 19 (FGF19) regulates several vital physiological processes, including bile acid, glucose, and lipid homeostasis. However, its therapeutic potential is limited by its structural instability. The purpose of this study is to express, purify, and characterize recombinant FGF19 to build the foundation for the creation of stable mutants, which can be used to treat a variety of common diseases including type 2 diabetes, atherosclerosis, and nonalcoholic fatty liver disease. The parameters for overexpression in Escherichia coli were optimized according to optical density, inducer concentration, …

Modeling Accuracy Matters: Aligning Molecular Dynamics With 2d Nmr Derived Noe Restraints, Milan Patel

Honors Scholar Theses

Among structural biology techniques, Nuclear Magnetic Resonance (NMR) provides a holistic view of structure that is close to protein structure in situ. Namely, NMR imaging allows for the solution state of the protein to be observed, derived from Nuclear Overhauser Effect restraints (NOEs). NOEs are a distance range in which hydrogen pairs are observed to stay within range of, and therefore experimental data which computational models can be compared against. To that end, we investigated the effects of adding the NOE restraints as distance restraints in Molecular Dynamics (MD) simulations on the 24 residue HP24stab derived villin headpiece subdomain to …

Determination Of Cadmium Uptake In Crassostrea Virginica Shell Under Controlled Conditions, Joseph John Pavelites Ii

<strong> Theses and Dissertations </strong>

The objective of this thesis was to meet growing demand for the development of environmental biomonitors that protect ecosystems and public health. To do this, I determined the potential of oyster shell as a bioindicator of cadmium (Cd) in the environment by determining the mode of Cd uptake and relationships between Cd concentrations in the environment, shell, and soft tissues of juvenile eastern oysters (Crassostrea virginica Gmelin). I performed a review of the literature on the ability of oyster shell to retain metal contaminants and the factors that could affect this process (Chapter 2). I then reared C. virginica …

The Role Of Cerium(Iii) In Bacterial Growth And The Microbial Transformation Of Aromatic Hydrocarbons, Shruti Sathish

Honors Theses

Biofilms are communities of surface-attached bacterial cells encased in an exopolymeric matrix. In this state, they are more resistant to antimicrobial treatment and can have adverse effects in medical, agricultural, and industrial settings. Whereas, as biocatalysts, biofilms from nonpathogenic bacteria enhance their performance and stability in catalysis. Unfortunately, there are several challenges when using bacteria in organic transformations due to their complex cellular chemistry. Trivalent lanthanide metals were discovered to serve regulatory roles in some bacterial catalytic processes, including those of Pseudomonas putida KT2440 (P. putida), a non-infectious Gram-negative bacterium. The main goal of our research is to use cerium(III) …

Characterizing The Roles Of The Variable Linker And Hub Domains In Camkii Activation, Noelle Dziedzic

Doctoral Dissertations

Learning and memory formation at the cellular level involves decoding complex electrochemical signals between nerve cells, or neurons. Understanding these processes at the molecular level requires a comprehensive study of calcium-sensitive proteins that serve as signal mediators within cells. More specifically, the protein calcium/calmodulin-dependent protein kinase II (CaMKII) is a key regulator of downstream cellular signaling events in the brain, playing an important role in long term memory formation. CaMKII is encoded in humans on four different genes: alpha, beta, gamma and delta. For added complexity, each of these gene products can be alternatively spliced and translated into multiple protein …

Mitochondrial Division: Synergizing In Mitochondrial Divisome, Ao Liu

Dartmouth College Ph.D Dissertations

Mitochondria are the energy factories of the cell. The dynamic nature of cells demands routine changes in mitochondrial morphology by fusion and division. The dynamin GTPase Drp1 is a central mitochondrial division protein, driving constriction of the outer mitochondrial membrane via oligomerization. At least four regulatory factors control Drp1 activity on the outer mitochondrial membrane (OMM): 1) receptor proteins (Mff, MiD49, MiD51, and Fis1); 2) actin filaments; 3) the mitochondrial phospholipid cardiolipin (CL); and 4) Drp1 post-translational modifications, of which two phosphorylation sites (S579 and S600) are the most well studied. However, the molecular mechanism of how these factors work …

Characterization Of Cl-Par-4: Wt Vs. Mutant, Samjhana Pandey, Krishna K. Raut, Andrea M. Clark, Antoine Baudin, Lamya Djemri, David S. Libich, Steven M. Pascal

The Graduate School Posters

Intrinsically disordered proteins (IDPs) play important roles in regulation of cell signaling pathways as well as cellular processes. Dysregulation of these proteins is associated with several human diseases. Prostate apoptosis response-4 (Par-4), a proapoptotic tumor suppressor protein, is categorized as an intrinsically disordered protein and downregulation of this protein has been reported in myriad of cancers including glioma, breast cancers, and prostate cancers. The caspase-cleaved fragment of Par-4 (cl-Par-4) plays an active role in tumor suppression by inhibiting several cell survival pathways.

Here, we employed site-directed mutagenesis to introduce a point mutation in the cl-Par-4 wildtype (WT) to generate the …

Structural Files For The Etr1 Ethylene-Receptor Dimer Based On Computational Modeling, Beenish J. Azhar, Safdar Abbas, Sitwat Aman, Maria V. Yamburenko, Wei Chen, Lena Muller, Buket Uzun, David A. Jewell, Jian Dong, Samina N. Shakeel, Georg Groth, Brad M. Binder, Gevorg Grigoryan, G. Eric Schaller

Dartmouth Scholarship

Structural models for the ETR1 homodimer were generated with AlphaFold-Multimer. Coppers were modeled under two potential coordinations involving Cys65 and His69 of the ETR1 homodimer, one in which the two coppers are bound independently and do not share an interaction with each other, and another where they are closely bonded.

See the following publication for details: Azhar, B.J., Abbas, S., Aman, S., Yamburenko, M.V., Chen, W., Müller, L., Uzun, B., Jewell, D.A., Dong, J., Shakeel, S.N., Groth, G., Binder, B.M., Grigoryan, G., Schaller, G.E. (2023) Basis for high-affinity ethylene binding by the ethylene receptor ETR1 of Arabidopsis. Proc. Natl. Acad. …