Bioinformatics Commons^™

Retro-Structural Analysis Of The Four Helix Bundle Motif In Binuclear Proteins, Walker Pedigo, Maggie Smith

Honors Theses

Protein structure is directly related to protein function. There are four levels of protein structure: primary, secondary, tertiary, and quaternary. The interactions amongst the structural components of a protein give rise to its unique characteristics. The four helix bundle motif is a common structural trait in a variety of binuclear proteins. In this study, PyMOL, a molecular visualization system, was used to analyze binuclear proteins that possess a four helix bundle. Images of proteins containing dicopper, diiron, and dimanganese sites were captured. The images were compiled into figures for each individual protein. After creating the figures, each protein was further …

Comparative Modeling And Evolutionary Comparison Of Serine Protease, A Timber Rattlesnake Venom Protein, Qawer Ayaz

Theses

The aim of this study is to create a homology model of VG35 serine protease and evaluate the evolutionary comparison of secondary structure on basis of protein model using YASARA. This method was furthermore used to predict the potential epitopes which can help in the investigation of future studies.

The VG35 was used to run a BLAST search which gave most resembled serine protease of different species which was then translated and modeled in YASARA. The modeled protein data was then used to determine the secondary structure. This was then used for evolutionary comparison of all proteins to VG35. Then …

A Chemical Interpretation Of Protein Electron Density Maps In The Worldwide Protein Data Bank, Sen Yao, Hunter N. B. Moseley

Molecular and Cellular Biochemistry Faculty Publications

High-quality three-dimensional structural data is of great value for the functional interpretation of biomacromolecules, especially proteins; however, structural quality varies greatly across the entries in the worldwide Protein Data Bank (wwPDB). Since 2008, the wwPDB has required the inclusion of structure factors with the deposition of x-ray crystallographic structures to support the independent evaluation of structures with respect to the underlying experimental data used to derive those structures. However, interpreting the discrepancies between the structural model and its underlying electron density data is difficult, since derived sigma-scaled electron density maps use arbitrary electron density units which are inconsistent between maps …

Computational Analysis Of Large-Scale Trends And Dynamics In Eukaryotic Protein Family Evolution, Joseph Boehm Ahrens

FIU Electronic Theses and Dissertations

The myriad protein-coding genes found in present-day eukaryotes arose from a combination of speciation and gene duplication events, spanning more than one billion years of evolution. Notably, as these proteins evolved, the individual residues at each site in their amino acid sequences were replaced at markedly different rates. The relationship between protein structure, protein function, and site-specific rates of amino acid replacement is a topic of ongoing research. Additionally, there is much interest in the different evolutionary constraints imposed on sequences related by speciation (orthologs) versus sequences related by gene duplication (paralogs). A principal aim of this dissertation is to …

Predicting Protein Residue-Residue Contacts Using Random Forests And Deep Networks, Joseph Luttrell Iv, Tong Liu, Chaoyang Zhang, Zheng Wang

Faculty Publications

Background: The ability to predict which pairs of amino acid residues in a protein are in contact with each other offers many advantages for various areas of research that focus on proteins. For example, contact prediction can be used to reduce the computational complexity of predicting the structure of proteins and even to help identify functionally important regions of proteins. These predictions are becoming especially important given the relatively low number of experimentally determined protein structures compared to the amount of available protein sequence data.

Results: Here we have developed and benchmarked a set of machine learning methods …

Automatic 13C Chemical Shift Reference Correction Of Protein Nmr Spectral Data Using Data Mining And Bayesian Statistical Modeling, Xi Chen

Theses and Dissertations--Molecular and Cellular Biochemistry

Nuclear magnetic resonance (NMR) is a highly versatile analytical technique for studying molecular configuration, conformation, and dynamics, especially of biomacromolecules such as proteins. However, due to the intrinsic properties of NMR experiments, results from the NMR instruments require a refencing step before the down-the-line analysis. Poor chemical shift referencing, especially for ¹³C in protein Nuclear Magnetic Resonance (NMR) experiments, fundamentally limits and even prevents effective study of biomacromolecules via NMR. There is no available method that can rereference carbon chemical shifts from protein NMR without secondary experimental information such as structure or resonance assignment.

To solve this problem, we …

Algorithms For Automated Assignment Of Solution-State And Solid-State Protein Nmr Spectra., Andrey Smelter

Electronic Theses and Dissertations

Protein nuclear magnetic resonance spectroscopy (Protein NMR) is an invaluable analytical technique for studying protein structure, function, and dynamics. There are two major types of NMR spectroscopy that are used for investigation of protein structure – solution-state and solid-state NMR. Solution-based NMR spectroscopy is typically applied to proteins of small and medium size that are soluble in water. Solid-state NMR spectroscopy is amenable for proteins that are insoluble in water. In the vast majority NMR-based protein studies, the first step after experiment optimization is the assignment of protein resonances via the association of chemical shift values to specific atoms in …

Testing The Independence Hypothesis Of Accepted Mutations For Pairs Of Adjacent Amino Acids In Protein Sequences, Jyotsna Ramanan, Peter Revesz

School of Computing: Faculty Publications

Evolutionary studies usually assume that the genetic mutations are independent of each other. However, that does not imply that the observed mutations are independent of each other because it is possible that when a nucleotide is mutated, then it may be biologically beneficial if an adjacent nucleotide mutates too. With a number of decoded genes currently available in various genome libraries and online databases, it is now possible to have a large-scale computer-based study to test whether the independence assumption holds for pairs of adjacent amino acids. Hence the independence question also arises for pairs of adjacent amino acids within …

Network Exploration Of Correlated Multivariate Protein Data For Alzheimer's Disease Association, Matthew J. Lane

Theses

Alzheimer Disease (AD) is difficult to diagnose by using genetic testing or other traditional methods. Unlike diseases with simple genetic risk components, there exists no single marker determining as to whether someone will develop AD. Furthermore, AD is highly heterogeneous and different subgroups of individuals develop the disease due to differing factors. Traditional diagnostic methods using perceivable cognitive deficiencies are often too little too late due to the brain having suffered damage from decades of disease progression. In order to observe AD at early stages prior to the observation of cognitive deficiencies, biomarkers with greater accuracy are required. By using …

Structure-Function Investigation Of Proteins Involved In Cellulose Biosynthesis By Escherichia Coli, Thomas Brenner

Theses and Dissertations (Comprehensive)

Bacteria thrive within multicellular communities called biofilms consisting of a self-produced matrix. Biofilm matrices improve bacterial adherence to surfaces while creating a barrier from host immune responses, disinfectants, antibiotics and other environmental factors. Persistent colonization by the widely distributed pathogens, Escherichia coli and Salmonella spp., has been linked to production of biofilms composed of the exopolysaccharide cellulose. Cellulose-containing biofilms are also important to Acetobacter, Sarcina, Rhizobium and Agrobacterium species to form symbiotic and pathogenic interactions. In Enterobacteriaceae, two operons (bcsABZC and bcsEFG) are proposed to encode for proteins that form a cellulose biosynthetic complex that spans the …

Testing The Independence Hypothesis Of Accepted Mutations For Pairs Of Adjacent Amino Acids In Protein Sequences, Jyotsna Ramanan

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Evolutionary studies usually assume that the genetic mutations are independent of each other. However, that does not imply that the observed mutations are independent of each other because it is possible that when a nucleotide is mutated, then it may be biologically beneficial if an adjacent nucleotide mutates too.

With a number of decoded genes currently available in various genome libraries and online databases, it is now possible to have a large-scale computer-based study to test whether the independence assumption holds for pairs of adjacent amino acids. Hence the independence question also arises for pairs of adjacent amino acids within …

Mutations Of Adjacent Amino Acid Pairs Are Not Always Independent, Jyotsna Ramanan, Peter Revesz

CSE Conference and Workshop Papers

Evolutionary studies usually assume that the genetic mutations are independent of each other. This paper tests the independence hypothesis for genetic mutations with regard to protein coding regions. According to the new experimental results the independence assumption generally holds, but there are certain exceptions. In particular, the coding regions that represent two adjacent amino acids seem to change in ways that sometimes deviate significantly from the expected theoretical probability under the independence assumption.

An Incremental Phylogenetic Tree Algorithm Based On Repeated Insertions Of Species, Peter Revesz, Zhiqiang Li

CSE Conference and Workshop Papers

In this paper, we introduce a new phylogenetic tree algorithm that generates phylogenetic trees by repeatedly inserting species one-by-one. The incremental phylogenetic tree algorithm can work on proteins or DNA sequences. Computer experiments show that the new algorithm is better than the commonly used UPGMA and Neighbor Joining algorithms.

An Exploration Of The Phylogenetic Placement Of Recently Discovered Ultrasmall Archaeal Lineages, Jeffrey M. O'Brien

Honors Scholar Theses

In recent years, several new clades within the domain Achaea have been discovered. This is due in part to microbiological sampling of novel environments, and the increasing ability to detect and sequence uncultivable organisms through metagenomic analysis. These organisms share certain features, such as small cell size and streamlined genomes. Reduction in genome size can present difficulties to phylogenetic reconstruction programs. Since there is less genetic data to work with, these organisms often have missing genes in concatenated multiple sequence alignments. Evolutionary Biologists have not reached a consensus on the placement of these lineages in the archaeal evolutionary tree. There …

Exploring The Effect Of Climate Change On Biological Systems, Nardos Sori

Chemistry & Biochemistry Theses & Dissertations

The present and potential future effect of global warming on the ecosystem has brought climate change to the forefront of scientific inquiry and discussion. For our investigation, we selected two organisms, one from cyanobacteria and one from a cereal plant to determine how climate change may impact these biological systems. The study involved understanding the physiological and adaptive responses at both the genetic and protein function levels to counteract environmental stresses. An increase in atmospheric carbon dioxide is a key factor in global climate change and can lead to alterations in ocean chemistry. Cyanobacteria are important, ancient and ubiquitous organisms …

Prediction Of The Protein Complex Assembly Pathway Using Multiple Docking Algorithm, Yoichiro Togawa

Open Access Theses

Proteins often function as a complex of multiple subunits, and the quaternary structure is important for proper function. An ordered assembly pathway is one of the strategies nature has developed to obtain the correct conformation: studies have shown a relationship between the assembly pathway and evolution of protein complexes. Identification of the assembly pathway and the intermediate structures helps drug development as well. Therefore, elucidation of the assembly pathway of protein complexes is important for understanding biochemical processes central to cellular function. Recent studies have demonstrated the assembly pathway of a protein complex can be predicted from its crystal structure …

How Long Is A Piece Of Loop?, Yoonjoo Choi, Sumeet Agarwal, Charlotte M. Deane

Dartmouth Scholarship

Loops are irregular structures which connect two secondary structure elements in proteins. They often play important roles in function, including enzyme reactions and ligand binding. Despite their importance, their structure remains difficult to predict. Most protein loop structure prediction methods sample local loop segments and score them. In particular protein loop classifications and database search methods depend heavily on local properties of loops. Here we examine the distance between a loop's end points (span). We find that the distribution of loop span appears to be independent of the number of residues in the loop, in other words the separation between …

Helix Turn Helix Domain, David J. Hall

Protein Domains

Helix turn helix domain #3V1A. The helix-turn helix is a DNA-binding domain. The two alpha helices are the reading or recognition helices, which bind in a groove in the DNA and recognize specific gene regulatory sequences in the DNA.

Ring Domain, David J. Hall

Protein Domains

Ring domain #1CHC. The RING finger is a specialized type of Zn finger consisting of 40–60 residues that binds two atoms of zinc, and is involved in mediating protein—protein interactions. Many zinc fingers bind nucleic acids. The presence of a RING finger domain is a characteristic of RING-class E3 ubiquitin protein ligases capable of transferring ubiquitin from an E2 enzyme to a substrate protein.

Sh2 Domain, David J. Hall

Protein Domains

SH2 domain #1BFJ. Src-homology 2 (SH2) domains are modules of ~100 amino acids that bind to specific phospho tyrosine (pY) containing peptide motifs. Conventional SH2 domains have a conserved pocket that recognizes pY, and a more variable pocket that binds 3-6 residues C-terminal to the pY and confers specificity.

Sh3 Domain, David J. Hall

Protein Domains

SH3 domain #1NEB. Src-homology 3 (SH3) domains bind to Pro-rich peptides that form a left-handed poly-Pro type II helix, with the minimal consensus Pro-X-X-Pro. Each Pro is usually preceeded by an aliphatic residue. Each in the aliphatic-Pro pair binds to a hydrophobic pocket on the SH3 domain.

Ig Domain, David J. Hall

Protein Domains

Ig domain #2CKN. This particular domain is named for the first protein in which it was found, the immunoglobulin. An immunoglobulin is a antibody. Antibodies are generated by our immune system to recognize the specific size, shape and charge of pathogens. This domain is also found on the extracellular portion of many receptors including the interleukin-1 family of receptors.

Beta Barrel, David J. Hall

Protein Domains

Beta barrel (cyan fluorescent protein) #4AR7. This fluorescent protein is a variation of green fluorescent protein from a jellyfish and is the only domain that is a complete protein. The protein is routinely used to visualize a variety of biological processes. The beta barrel domain is a beta sheet wrapped around the fluorescent active site to provide structure.

In Vitro Expression And Purification Of Class I Mhc Molecules, Loi Cheng

Honors Scholar Theses

The major histocompatibility complex (MHC) is a gene family responsible for many critical functions of the immune system in most vertebrates. The MHC consists of three classes differentiated by their structure and function, and MHC class I encodes antigen binding proteins as well as chaperone and accessory proteins such as tapasin. The purpose of this project is to reconstitute several human MHC class I molecules in their peptide-filled and peptide-deficient forms, and to purify these proteins for biochemical study. The expressed proteins include wild type and mutant variants of the fusion protein human leukocyte antigen HLA-B*0801-fos, and human beta-2-microglobulin (β2m). …