PROJECT SUMMARY/ABSTRACT
Interactions between proteins and DNA control several fundamental biological
processes, including gene regulation, DNA repair, replication, transcription, translation,
and recombination. The PI’s previous research in instrument design, biological mass
spectrometry, ion mobility spectrometry, and structural biology have enabled the study of
the intra- and inter- molecular interactions and conformational landscape that drive
protein, DNA, protein-protein and protein-DNA interactions in several model systems. The
goal of this project is to advance mass spectrometry (MS) based techniques with
complementary structural tools to better describe biomolecular complexes in their native
solution environment. Coupling solution- and gas- phase separations (e.g., accessible
solvent area labeling, ion-neutral reactions, and trapped ion mobility spectrometry), new
dissociation methods (e.g., electron- and UV- based methods) with new developments in
ultra-high, resolution MS will provide new structural biology tools capable of dissecting
the molecular complexity and energy landscape of protein isoforms and protein-DNA
complexes. These advanced MS tools will be used for the characterization of model
systems of the non-histone chromosomal HMG protein family (e.g., high mobility group
AT-hook 2 protein-HMGA2), type IA topoisomerase (TOP1) family and nucleosome
dynamics (e.g., interplay of histone composition and histone post-translational
modifications, PTMs). We will study HMGA2 transitions from unstructured to structured
that allow HMGA2 to be involved in multiple biological processes, including DNA
replication, translation, recombination, and gene regulation. We will capture the structural
intermediates of the TOP1-DNA complexes associated with the catalytic cycle to search
for new antibiotic candidates. We will study the influence of histone variants and PTMs
in the nucleosome dynamics (e.g., partial, and full assemble); nucleosome dissociation
and alteration of nucleosomal structure are crucial features by which chromatin regulates
gene expression and DNA replication. The development of MS-based technologies
capable of studying intrinsically disordered and dynamic biomolecular systems will
significantly advance our understanding of the biological machinery associated with
disease mechanisms, identification of therapeutic targets and disease prevention.