Abstract Body: Abdominal aortic aneurysms (AAA) carry high morbidity and mortality, particularly if rupture occurs. The mainstay of therapy is surgical, as current medical options are limited. Epigenetic control of inflammatory programs has emerged as a tractable axis in the development of AAAs. An epigenetic chromatin modifying enzyme recently reported in promoting AAA is SET Domain Bifurcated 2 (SETDB2). SETDB2 is a histone methyltransferase that places the transcription repressive H3K9me3 mark at gene promoter sites for the tissue inhibitor of metalloproteinases in endothelial cells and macrophages thus promoting AAA formation. Yet, its full-length structure and druggability remain undefined. We hypothesized that SETDB2 harbors a conserved, druggable catalytic pocket and displays measurable H3K9 methyltransferase activity in-vitro that depends on pocket-proximal residues. We approached this hypothesis in two modalities – in-silico and in-vitro. Our in-silico analysis predicted a full-length SETDB2 structure with high confidence (predicted local distance difference test - pLDDT [ ~61]; predicted template modeling - pTM [ ~0.58]). After energy minimization, orthogonal pocket detectors identified a contiguous cofactor/peptide cavity. Ensemble docking supported ligandability with best Vina scores of S-adenosyl methionine (SAM) = −5.12 kcal/mol and H3K9me0 peptide = −5.997 kcal/mol, with poses consistent with catalytic geometry and conserved hydrogen bonds. To validate this experimentally, we developed a novel protein production method for recombinant human SETDB2 from Hi5 insect cell (baculovirus) expression such that it is secreted into media and not toxic to the host vector. SETDB2 was purified by nickel affinity with gel-filtration cleanup, and assessed by SDS-PAGE. Binding affinity to H3K9me0 peptide ligand was assessed by surface plasmon resonance and electron microscopy for biophysical structure determination. We report our work towards the first full structure of SETDB2 in apo and active form using both in-silico and experimental methodology. Future analysis will focus on bioassay development to aid in cell-specific therapeutic targeting using high throughput experimentation and direct-to-biology techniques.