A5031228208- RNA and protein synthesis mechanisms
- Mitochondrial Function and Pathology
- RNA Research and Splicing
- Metabolism and Genetic Disorders
- RNA modifications and cancer
- Bacterial Genetics and Biotechnology
- ATP Synthase and ATPases Research
- DNA and Nucleic Acid Chemistry
- DNA Repair Mechanisms
- Bacteriophages and microbial interactions
- Metabolomics and Mass Spectrometry Studies
- Fungal and yeast genetics research
- Genomics and Chromatin Dynamics
- Molecular Biology Techniques and Applications
- Toxin Mechanisms and Immunotoxins
- Microbial Natural Products and Biosynthesis
- Photosynthetic Processes and Mechanisms
- Advanced biosensing and bioanalysis techniques
- Glycosylation and Glycoproteins Research
- CRISPR and Genetic Engineering
- Enzyme Structure and Function
- Transgenic Plants and Applications
- Enterobacteriaceae and Cronobacter Research
- Powdery Mildew Fungal Diseases
- Ubiquitin and proteasome pathways
Thomas Jefferson University
2018-2025
Philadelphia University
2025
Sidney Kimmel Cancer Center
2018-2021
Rowan University
2009-2019
Ludwig-Maximilians-Universität München
2014
Center for Integrated Protein Science Munich
2014
Stratford University
2007-2012
Rutgers, The State University of New Jersey
2009
SUNY Downstate Health Sciences University
2002-2005
State University of New York
1998-2000
Human mitochondrial transcription is driven by a single subunit RNA polymerase and set of basal factors. The development recombinant in vitro system has allowed for detailed molecular characterization the individual components their contribution to initiation. We found that TFAM TFB2M act synergistically increase efficiency 100–200-fold as compared with alone. Both light-strand promoter (LSP) HSP1 promoters displayed maximal levels when was present an amount equimolar DNA template....
Coordinated replication and expression of the mitochondrial genome is critical for metabolically active cells during various stages development. However, it not known whether transcription can occur simultaneously without interfering with each other DNA copy number be regulated by machinery. We found that interaction human elongation factor TEFM RNA polymerase nascent transcript prevents generation primers increases processivity thereby serves as a molecular switch between transcription,...
In live cells, phase separation is thought to organize macromolecules into membraneless structures known as biomolecular condensates. Here, we reconstituted transcription in condensates from purified mitochondrial components using optimized vitro reaction conditions probe the structure–function relationships of We find that core mt-transcription machinery form multiphasic, viscoelastic vitro. Strikingly, rates condensate-mediated are substantially lower than solution. The decrease...
The mitochondrial genome is transcribed by a single-subunit T7 phage-like RNA polymerase (mtRNAP), structurally unrelated to cellular RNAPs. In higher eukaryotes, mtRNAP requires two transcription factors for efficient initiation—TFAM, major nucleoid protein, and TFB2M, transient component of catalytic site. mechanisms behind assembly the machinery its regulation are poorly understood. We isolated identified previously unknown human intermediate—a pre-initiation complex that includes mtRNAP,...
Mitochondrial transcription factor A (TFAM) is essential for the maintenance, expression and transmission of mitochondrial DNA (mtDNA). However, mechanisms post-translational regulation TFAM are poorly understood. Here, we show that lysine acetylated within its high-mobility-group box 1, a domain can also be serine phosphorylated. Using bulk single-molecule methods, demonstrate site-specific phosphoserine acetyl-lysine mimics human regulate interaction with non-specific through distinct...
Bacterial and eukaryotic nuclear RNA polymerases (RNAPs) cap with the oxidized reduced forms of metabolic effector nicotinamide adenine dinucleotide, NAD+ NADH, using NADH as non-canonical initiating nucleotides for transcription initiation. Here, we show that mitochondrial RNAPs (mtRNAPs) do so more efficiently than RNAPs. Direct quantitation NAD+- NADH-capped demonstrates remarkably high levels capping in vivo: up to ~60% yeast transcripts, ~15% human transcripts. The efficiency is...
Cancer is a leading cause of death men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority cancer deaths. Extracellular receptors modified by α2,3-sialic acids promote this can serve as ideal chemotherapeutic targets. For example, extracellular domain mucin receptor podoplanin (PDPN) highly O-glycosylated with acid linked galactose. PDPN activated endogenous ligands induce tumor metastasis. Dietary lectins target proteins containing...
Regulation of transcription mtDNA is thought to be crucial for maintenance redox potential and vitality the cell but poorly understood at molecular level. In this study we mapped binding sites core initiation factors TFAM TFB2M on human mitochondrial RNA polymerase, interactions latter with promoter DNA. This allowed us construct a detailed structural model, which displays remarkable level interaction between components complex (IC). The architecture IC suggests mechanisms recognition that...
Members of the Pol A family DNA polymerases, found across all domains life, utilize various strategies for strand separation during replication. In higher eukaryotes, mitochondrial polymerase γ relies on replicative helicase TWINKLE, whereas yeast ortholog, Mip1, can unwind independently. Using Mip1 as a model, we present series high-resolution cryo-EM structures that capture process displacement. Our data reveal previously unidentified structural elements facilitate unwinding downstream...
Maackia amurensis lectins, including MASL, MAA, and MAL2, are widely utilized in biochemical medicinal research. However, the structural functional differences between these lectins have not been defined. Here, we present a high-resolution cryo-EM structure of MASL revealing that its tetrameric assembly is directed by two intersubunit disulfide bridges. These bridges, formed C272 residues, central to dimer-of-dimers tetramer. This also identifies residues involved stabilizing dimer...
Transcription in human mitochondria is driven by a core apparatus consisting of Pol A family RNA polymerase (mtRNAP), the initiation factors TFAM and TFB2M, elongation factor TEFM. While earlier structures complexes provided valuable snapshots, they represent isolated stages highly dynamic multistep process. Critical aspects mitochondrial transcription - such as DNA recognition melting, promoter escape, release remain poorly understood. Here, we present series cryo-EM that capture complex it...
During the early stages of transcription, T7 RNA polymerase forms an unstable initiation complex that synthesizes and releases transcripts 2–8 nt in length before disengaging from promoter isomerizing to a stable elongation complex. In this study, we used RNA⋅protein RNA⋅DNA crosslinking methods probe location newly synthesized halted complexes. The results indicate remains hybrid for about 8 site nucleotide addition emerges surface enzyme 12 site. Strikingly, as transcript leaves its with...