A5033220113- RNA regulation and disease
- RNA and protein synthesis mechanisms
- RNA Research and Splicing
- Enzyme Structure and Function
- Cellular transport and secretion
- RNA modifications and cancer
- Microtubule and mitosis dynamics
- Viral Infections and Immunology Research
- Toxin Mechanisms and Immunotoxins
- Drug Transport and Resistance Mechanisms
- DNA and Nucleic Acid Chemistry
- Plant Virus Research Studies
- Biochemical and Molecular Research
- Infective Endocarditis Diagnosis and Management
- Trace Elements in Health
- Amoebic Infections and Treatments
- Microbial Metabolic Engineering and Bioproduction
- Crystallization and Solubility Studies
- Protein purification and stability
- Endoplasmic Reticulum Stress and Disease
- Tuberculosis Research and Epidemiology
- Peptidase Inhibition and Analysis
- HIV/AIDS drug development and treatment
- Enzyme Catalysis and Immobilization
- Protein Structure and Dynamics
Butler University
2017-2024
Bridge University
2024
Carnegie Mellon University
2011-2014
Howard Hughes Medical Institute
2004-2007
University of Utah
2004-2007
University of Chicago
1999
We report the crystal structure of catalytic domain human ADAR2, an RNA editing enzyme, at 1.7 angstrom resolution. The reveals a zinc ion in active site and suggests how substrate adenosine is recognized. Unexpectedly, inositol hexakisphosphate (IP 6 ) buried within enzyme core, contributing to protein fold. Although there are no reports that deaminases act on (ADARs) require cofactor, we show IP required for activity. Amino acids coordinate conserved some transfer (tRNA) (ADATs), related...
Biogenesis of the ribbon-like membrane network mammalian Golgi requires tethering by conserved GRASP domain in GRASP65 and GRASP55, yet mechanism is not fully understood. Here, we report crystal structure GRASP55 domain, which revealed an unusual arrangement two tandem PDZ folds that more closely resemble prokaryotic domains. Biochemical functional data indicated interaction between ligand-binding pocket PDZ1 internal ligand on PDZ2 mediates self-interaction, structural analyses suggest this...
Adenosine deaminases that act on RNA (ADARs) catalyze adenosine to inosine conversion in is largely double stranded. Human ADAR2 (hADAR2) contains two double-stranded binding motifs (dsRBMs), separated by a 90-amino acid linker, and these are followed the C-terminal catalytic domain. We assayed enzymatic activity of N-terminal deletion constructs hADAR2 determine role dsRBMs intervening linker peptide. found truncated protein consisting one dsRBM deaminase domain was capable deaminating...
Mitotic phosphorylation of the conserved GRASP domain GRASP65 disrupts its self-association, leading to a loss Golgi membrane tethering, cisternal unlinking, and breakdown. Recently, structural basis self-interaction was determined, yet mechanism by which this activity is unknown. Here, we present crystal structure phosphomimic containing an aspartic acid substitution for serine residue (Ser-189) that in phosphorylated PLK1, causing block tethering ribbon formation. The revealed...
Deamination at C6 of adenosine in RNA catalyzed by the ADAR enzymes generates inosine corresponding position. Because is decoded as guanosine during translation, this modification can lead to codon changes messenger RNA. Hydration 8-azanebularine across C6−N1 double bond an excellent mimic transition state proposed for hydrolytic deamination reaction ADARs. Here, we report synthesis a phosphoramidite and its use preparation RNAs mimicking secondary structure found known editing site...
Abstract Mycobacterium tuberculosis virulence is highly metal‐dependent with metal availability modulating the shift from dormant to active states of M. infection. Rv0045c a proposed metabolic serine hydrolase whose folded stability dependent on divalent concentration. Herein, we measured inhibition profile enzymatic activity and found specific transition cations (Cu 2+ ≥ Zn > Ni Co ) strongly inhibited its activity. The bind allosterically, largely affecting values for k cat rather than...
The RNA lariat debranching enzyme, Dbr1, is a metallophosphoesterase that cleaves 2'-5' phosphodiester bonds within intronic lariats. Previous reports have indicated Dbr1 enzymatic activity supported by diverse metal ions including Ni2+ , Mn2+ Mg2+ Fe2+ and Zn2+ . While in initial structures of the Entamoeba histolytica only one two catalytic metal-binding sites were observed to be occupied (with ion), recent determined /Fe2+ heterobinucleation. We solved high-resolution X-ray crystal...
Microgravity has been shown to be an excellent tool for protein crystal formation. A retrospective analysis of all publicly available crystallization data, including many that have not yet published, clearly demonstrates the value microgravity environment producing superior crystals. The parameters in database (the Butler Protein Crystal Database, BμCDB) were evaluated pertain both morphology and diffraction quality. Success metrics determined as improvements size, definition, uniformity,...
Serine hydrolases are a large category of enzymes that play vital roles in all forms life. In humans, they can serve as targets for drugs and the building blocks development new antibiotics. be further subclassified into group called carbohydrate esterase family 7 (CE7) which hydrolyze ester bonds substrates. This project focuses on TM0077, an acetyl isolated from Thermotoga maritima, is specific enzyme member CE7 uses catalytic triad to functional groups Previous studies have determined...
RNA‐lariat Debranching Enzyme (Dbr1p) hydrolyzes the 2′‐5′ phosphodiester bond between intronic, adenosine branch point and 5′ end of intron. Intron lariat debranching is essential for processing snoRNAs miRNAs efficient intron turnover. Interestingly, Dbr1p null mutants have been shown to be defective in Ty1 retrotransposition Saccharomyces cerevisiae . Additionally, siRNA knockdown DBR1 a eukaryotic cell line has inhibited HIV‐1 replication, making characterization structure determination...
Adenosine Deaminase tRNA Specific 1 (ADAT1) is an enzyme in the adenosine deaminase acting on RNA (ADAR) family that causes site‐specific mutation eukaryotic tRNA. deamination by ADAT1 changes nucleotide to inosine, impacting control of specific genetic programs. These enzymes do not have double stranded binding motifs like ADARs but instead share catalytic domain ADAR. While structures for several ADAR been determined, there are no ADAT1. This research seeks determine structure from C....
Transmission of genetic information from DNA to protein passes through a messenger‐RNA intermediate. This mRNA is extensively processed after transcription, and one enzyme that does so denosine d e minase acts on R NA (ADAR). ADARs catalyze the deamination adenosines into inosines double‐stranded RNA (dsRNA) substrates, ultimately leading mutation in their encoded protein. These mutations are essential not only for properly functioning nervous system, but survival. The ADAR composed two...