A5087512728- Folate and B Vitamins Research
- Porphyrin Metabolism and Disorders
- RNA modifications and cancer
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- RNA and protein synthesis mechanisms
- Biochemical and Molecular Research
- Metalloenzymes and iron-sulfur proteins
- RNA Research and Splicing
- Heme Oxygenase-1 and Carbon Monoxide
- Crystallography and molecular interactions
- Mitochondrial Function and Pathology
- Inorganic Chemistry and Materials
- Plant biochemistry and biosynthesis
- Metabolism and Genetic Disorders
- Organometallic Complex Synthesis and Catalysis
- Nanocluster Synthesis and Applications
- Metal complexes synthesis and properties
- Epigenetics and DNA Methylation
- Metal-Catalyzed Oxygenation Mechanisms
- Insect Resistance and Genetics
- Iron Metabolism and Disorders
- Enzyme Structure and Function
- Photosynthetic Processes and Mechanisms
- Marine Toxins and Detection Methods
University of Michigan
2010-2025
Michigan United
2025
Uniformed Services University of the Health Sciences
2012-2017
Czech Academy of Sciences, Institute of Organic Chemistry and Biochemistry
2009
Charles University
2009
National Centre of Scientific Research "Demokritos"
2005
Lawrence Berkeley National Laboratory
2005
University of Crete
2005
Argonne National Laboratory
2005
University of California, Davis
2005
Mercaptopyruvate sulfurtransferase (MST) is a source of endogenous H2S, gaseous signaling molecule implicated in wide range physiological processes. The contribution MST versus the other two H2S generators, cystathionine β-synthase and γ-cystathionase, has been difficult to evaluate because many studies on have conducted at high pH used varied reaction conditions. In this study, we expressed, purified, crystallized human presence substrate 3-mercaptopyruvate (3-MP). kinetics production by...
Ribonuclease P (RNase P) catalyzes the maturation of 5′ end tRNA precursors. Typically these enzymes are ribonucleoproteins with a conserved RNA component responsible for catalysis. However, protein-only RNase (PRORP) process precursor tRNAs in human mitochondria and all tRNA-using compartments Arabidopsis thaliana . PRORP nuclear encoded among many eukaryotes, having evolved recently as yeast mitochondrial genomes encode an RNA. Here we report crystal structure PRORP1 from A. at 1.75 Å...
Itaconate brings metalloenzyme to a halt Controlled radicals enable unusual enzymatic transformations, but radical generation and management require dedicated systems. Ruetz et al. investigated how the immunometabolite itaconate might undermine these intricate systems inhibit propionate metabolism, crucial metabolic pathway in pathogenic Mycobacterium tuberculosis (Mtb) (see Perspective by Boal). They found that coenzyme A (CoA) derivative of can irreversibly enzyme methylmalonyl-CoA mutase...
Ribonucleic acids (RNAs) remain challenging targets for structural biology, creating barriers to understanding their vast functions in cellular biology and fully realizing applications biotechnology. The inherent dynamism of RNAs creates numerous obstacles capturing biologically relevant higher-order structures (HOSs), as a result, many RNA unknown. In this study, we describe the development native ion mobility-mass spectrometry collision-induced unfolding (CIU) characterization variety...
The catalytic potential for H 2 S biogenesis and homocysteine clearance converge at the active site of cystathionine β-synthase (CBS), a pyridoxal phosphate-dependent enzyme. CBS catalyzes β-replacement reactions either serine or cysteine by to give water S, respectively. In this study, high-resolution structures full-length enzyme from Drosophila in which carbanion (1.70 Å) an aminoacrylate intermediate (1.55 have been captured are reported. Electrostatic stabilization zwitterionic is...
Cobalamin-dependent methionine synthase (MetH) is a modular protein that catalyzes the transfer of methyl group from methyltetrahydrofolate to homocysteine produce and tetrahydrofolate. The cobalamin cofactor, which serves as both acceptor donor group, oxidized once every approximately 2,000 catalytic cycles must be reactivated by uptake an electron reduced flavodoxin S-adenosyl-L-methionine (AdoMet). Previous structures C-terminal fragment MetH (MetH(CT)) revealed reactivation conformation...
Significance Pseudouridine is among the most-abundant RNA modifications. We present a framework for conceptualizing how eukaryotic pseudouridine synthases select their substrates. This work reveals structure of yeast synthase 7 (Pus7) and presents cell-based biochemical investigations enzyme binding activity. demonstrate that Pus7 interacts promiscuously with RNAs containing UG U AR sequences. Our observations raise question why these enzymes only modify <5% sequences in transcriptome,...
We demonstrate that purified recombinant human betainehomocysteine methyltransferase-2 (BHMT-2) is a zinc metalloenzyme uses S-methylmethionine (SMM) as methyl donor for the methylation of homocysteine. Unlike highly homologous betaine-homocysteine methyltransferase (BHMT), BHMT-2 cannot use betaine. The K(m) SMM was determined to be 0.94 mm, and it has turnover number similar BHMT. Several compounds were tested inhibitors BHMT BHMT-2. SMM-specific activity not inhibited by dimethylglycine...
[NEt4][FeCl4], [P(C6H5)4][FeCl4], and [NEt4]2[Fe2S2Cl4] have been examined using 57Fe nuclear resonance vibrational spectroscopy (NRVS). These complexes serve as simple models for Fe−S clusters in metalloproteins. The partial density of states (PVDOS) spectra were interpreted by computation the normal modes assuming Urey−Bradley force fields, additional information from infrared Raman spectra. Previously published constants used initial values; new constraints NRVS frequencies amplitudes...
Ferroptosis is a non-apoptotic form of cell death resulting from the iron-dependent accumulation lipid peroxides. Colorectal cancer (CRC) cells accumulate high levels intracellular iron and reactive oxygen species (ROS) are thus particularly sensitive to ferroptosis. The compound (S)-RSL3 ([1S,3R]-RSL3) commonly used ferroptosis inducing that currently characterized as selective inhibitor selenocysteine containing enzyme (selenoprotein) Gluathione Peroxidase 4 (GPx4), an utilizes glutathione...
Abstract Methylenetetrahydrofolate reductase (MTHFR) is a pivotal flavoprotein connecting the folate and methionine methyl cycles, catalyzing conversion of methylenetetrahydrofolate to methyltetrahydrofolate. Human MTHFR ( h MTHFR) undergoes elaborate allosteric regulation involving protein phosphorylation S -adenosylmethionine (AdoMet)-dependent inhibition, though other factors such as subunit orientation FAD status remain understudied due lack functional structural model. Here, we report...
Enzymes possessing catalytic zinc centers perform a variety of fundamental processes in nature, including methyl transfer to thiols. Cobalamin-independent (MetE) and cobalamin-dependent (MetH) methionine synthases are two such enzyme families. Although they the same net reaction, group from methyltetrahydrofolate homocysteine (Hcy) form methionine, display markedly different strategies, modular organization, active site centers. Here we report crystal structures zinc-replete MetE MetH, both...
Ribonuclease P (RNase P) catalyzes the maturation of 5' end precursor-tRNAs (pre-tRNA) and is conserved in all domains life. However, composition RNase varies from bacteria to archaea eukarya, making one most diverse enzymes characterized. Most known contain a large catalytic RNA subunit that associates with 10 proteins. Recently, protein-only form was discovered mitochondria chloroplasts many higher eukaryotes. This proteinaceous (PRORP) represents new class metallonucleases. Here we...
Abstract B 12 antivitamins are important and robust tools for investigating the biological roles of vitamin . Here, potential antivitamin 2,4‐difluorophenylethynylcobalamin (F2PhEtyCbl) was prepared, its 3D structure studied in solution crystal. Chemically inert F2PhEtyCbl resisted thermolysis Co−C bond at 100 °C, stable bright daylight, also remained intact upon prolonged storage aqueous room temperature. It binds to human ‐processing enzyme CblC with high affinity ( K D =130 n m ) presence...
Proteins encoded by mitochondrial DNA are translated using mitochondrially tRNAs and rRNAs. As with nuclear tRNAs, must be processed to become fully functional. The form of ribonuclease P (mt:RNase P) is responsible for 5′-end maturation comprised three proteins; RNase protein (MRPP) 1 2 together proteinaceous (PRORP). However, its mechanism impact on development not yet known. Using homology searches, we have identified the proteins composing Drosophila mt:RNase P: Mulder (PRORP), Scully...
The CblC and CblD chaperones are involved in early steps the cobalamin trafficking pathway. Cobalamin derivatives entering cytoplasm converted by to a common cob(II)alamin intermediate via glutathione-dependent alkyltransferase or reductive elimination activities. Cob(II)alamin is subsequently one of two biologically active alkylcobalamins downstream chaperones. function has been elusive although it known form complex with under certain conditions. Here, we report that provides sulfur ligand...
We have used transient absorption spectroscopy in the UV–visible and X-ray regions to characterize excited state of CarH, a protein photoreceptor that uses form B12, adenosylcobalamin (AdoCbl), sense light. With visible excitation, nanosecond-lifetime photoactive is formed with unit quantum yield. The time-resolved near edge structure difference spectrum this demonstrates AdoCbl CarH undergoes only modest structural expansion around central cobalt, behavior similar observed for...
B(12)-dependent methionine synthase (MetH) from Escherichia coli is a large modular protein that alternately methylated by methyltetrahydrofolate to form methylcobalamin and demethylated homocysteine cob(I)alamin. Major domain rearrangements are required allow cobalamin react with three different substrates: homocysteine, methyltetrahydrofolate, S-adenosyl-l-methionine (AdoMet). These same appear preclude crystallization of the wild-type enzyme. Disulfide cross-linking was used lock...
Abstract Ferroptosis is a non-apoptotic form of cell death driven by iron-dependent lipid peroxide accumulation. Colorectal cancer (CRC) cells feature elevated intracellular iron and reactive oxygen species (ROS) that heighten ferroptosis sensitivity. The inducer (S)-RSL3 ([1S,3R]-RSL3) widely described as selective inhibitor the selenocysteine-containing enzyme (selenoprotein) glutathione peroxidase 4 (GPX4), which detoxifies peroxides utilizing glutathione. However, through chemical...
Ribonucleic acids (RNAs) are challenging structural biology targets, as numerous barriers exist to determining their high-resolution structures and specific biological functions. Previous results have highlighted the utility of collision-induced unfolding (CIU) relatively rapidly assess noncoding (nc)RNA higher-order structure (HOS) information. Yet, there remain many gaps in our understanding how these data can be related adopted by RNAs solution current correlations largely qualitative. In...