A5079270439- DNA and Nucleic Acid Chemistry
- DNA Repair Mechanisms
- Force Microscopy Techniques and Applications
- Advanced biosensing and bioanalysis techniques
- Advanced Electron Microscopy Techniques and Applications
- RNA and protein synthesis mechanisms
- Genomics and Chromatin Dynamics
- Bacteriophages and microbial interactions
- RNA Interference and Gene Delivery
- Advanced Fluorescence Microscopy Techniques
- Epigenetics and DNA Methylation
- RNA Research and Splicing
- Bacterial Genetics and Biotechnology
- Monoclonal and Polyclonal Antibodies Research
- Endoplasmic Reticulum Stress and Disease
- Receptor Mechanisms and Signaling
- Protein purification and stability
- Ubiquitin and proteasome pathways
- Microbial Natural Products and Biosynthesis
- Polyomavirus and related diseases
- Genomics and Phylogenetic Studies
- Orbital Angular Momentum in Optics
- Enzyme Structure and Function
- Genetic factors in colorectal cancer
- RNA regulation and disease
University of Würzburg
2015-2024
Leibniz Association
2013
University of Gdańsk
2013
University of Kentucky
2012
University of North Carolina at Chapel Hill
2005-2011
National Institutes of Health
2008
National Institute of Environmental Health Sciences
2008
University of Connecticut
2006
University of Nottingham
2003-2005
Single-stranded DNA is an effective noncovalent dispersant for individual single-walled carbon nanotubes (CNTs) in aqueous solution, forming a CNT−DNA hybrid material that has advantages CNT separations and applications. Atomic force microscopy (AFM) reveals regular pattern on the surface of CNT−DNA. We found this to be independent length sequence wrapping DNA, yet different from structures observed CNTs dispersed with sodium dodecyl sulfate absence DNA. wrapped thiol-modified form stable...
DNA mismatch repair is initiated by the recognition of mismatches MutS proteins. The mechanism which searches for and recognizes subsequently signals remains poorly understood. We used single-molecule analyses atomic force microscopy images MutS-DNA complexes, coupled with biochemical assays, to determine distributions conformational states, binding affinities, ATPase activities wild type two mutants MutS, alanine substitutions in conserved Phe-Xaa-Glu motif. find that on homoduplex DNA,...
Gephyrin is a trimeric protein involved in the final steps of molybdenum-cofactor (Moco) biosynthesis and clustering inhibitory glycine GABA A receptors at postsynaptic specializations. Each protomer consists stably folded domains (referred to as G E domains) located either terminus connected by proteolytically sensitive linker ∼150 residues. Both terminal can oligomerize their isolated forms; however, context full-length only G-domain trimer permanently present, whereas E-domain...
Quantum dots (QDs) possess highly desirable optical properties that make them ideal fluorescent labels for studying the dynamic behavior of proteins. However, a lack characterization methods reliably determining protein−quantum dot conjugate stoichiometry and functionality has impeded their widespread use in single-molecule studies. We used atomic force microscopic (AFM) imaging to demonstrate 1:1 formation UvrB−QD conjugates based on an antibody-sandwich method. show agarose gel-based...
Abstract The cell division cycle protein 45 (Cdc45) represents an essential replication factor that, together with the Mcm2-7 complex and four subunits of GINS, forms replicative DNA helicase in eukaryotes. Recombinant human Cdc45 (hCdc45) was structurally characterized its DNA-binding properties were determined. Synchrotron radiation circular dichroism spectroscopy, dynamic light scattering, small-angle X-ray scattering atomic force microscopy revealed that hCdc45 exists as alpha-helical...
The ability of DNA glycosylases to rapidly and efficiently detect lesions among a vast excess nondamaged bases is vitally important in base excision repair (BER). Here, we use single molecule imaging by atomic force microscopy (AFM) supported 2-aminopurine fluorescence flipping assay study damage search human thymine glycosylase (hTDG), which initiates BER mutagenic cytotoxic G:T G:U mispairs DNA. Our data reveal an equilibrium between two conformational states hTDG-DNA complexes, assigned...
Cell division cycle protein 45 (Cdc45) is an essential component of the eukaryotic replicative DNA helicase. We found that human Cdc45 forms a complex with single-stranded (ssDNA) binding RPA. Moreover, it actively loads RPA onto nascent ssDNA. Pull-down assays and surface plasmon resonance studies revealed Cdc45-bound complexed ssDNA in 8-10 nucleotide mode, but dissociated when covered 30-mer. Real-time analysis RPA-ssDNA demonstrated catalytically loaded This placement reaction required...
SignificanceWe directly visualize DNA translocation and lesion recognition by the O6-alkylguanine alkyltransferase (AGT). Our data show bidirectional movement of AGT monomers clusters on undamaged that depended Zn2+ occupancy AGT. A role cooperative in enhancing search efficiencies has previously been proposed. Surprisingly, our no enhancement speed cluster formation, suggesting may serve a different function. support preferential formation at alkyl lesions, these stabilizing lesion-bound...
The dsRNA-activated protein kinase, PKR, plays a pivotal role in the cellular antiviral response. PKR contains an N-terminal dsRNA binding domain (dsRBD) and C-terminal kinase domain. An autoinhibition model has been proposed which latent exists closed conformation where substrate cleft of is blocked by dsRBD. Binding to activates enzyme inducing open enhancing dimerization. We have tested this characterizing affinity kinetics nucleotide PKR. fluorescent mant-AMPPNP binds unactivated with Kd...
O 6 -Alkylguanine-DNA alkyltransferase (AGT) repairs mutagenic -alkylguanine and 4 -alkylthymine adducts in DNA, protecting the genome also contributing to resistance of tumors chemotherapeutic alkylating agents. AGT binds DNA cooperatively, cooperative interactions are likely be important lesion search repair. We examined morphologies complexes on long, unmodified DNAs, using analytical ultracentrifugation atomic force microscopy. formed clusters ≤11 proteins. Longer clusters, predicted by...
DNA replication is a central process in all living organisms. Polyomavirus serves as model system for eukaryotic and has considerably contributed to our understanding of basic mechanisms. However, the details involved processes are still unclear, particular regarding lagging strand synthesis. To delineate complex mechanism coordination various cellular proteins binding simultaneously or consecutively initiate replication, we investigated single-stranded (ssDNA) interactions by SV40 large T...
Abstract Optical tweezers were employed to investigate the effects of small DNA-binding molecules on low-force (≤ 15 pN) stretching behaviour single DNA molecules. As canonical B-DNA helix is not perturbed in this force regime, elasticity observed upon drug binding provide useful insight into how drugs may alter vivo processes. In study, agents with different modes analysed. force—extension curves recorded presence netropsin, a purely minor groove-binding antibiotic drug, ethidium bromide,...