Protein target This record contains the predicted 3D structure of human microtubule-associated protein tau (MAPT / tau protein, UniProt P10636, 758 amino acids, canonical isoform), generated using the E8 Navigator — a symmetry-based, non-data-driven protein folding method.MAEPRQEFEVMEDHAGTYGLGDRKDQGGYTMHQDQEGDTDAGLKESPLQTPTEDGSEEPGSETSDAKSTPTAEDVTAPLVDEGAPGKQAAAQPHTEIPEGTTAEEAGIGDTPSLEDEAAGHVTQEPESGKVVQEGFLREPGPPGLSHQLMSGMPGAPLLPEGPREATRQPSGTGPEDTEGGRHAPELLKHQLLGDLHQEGPPLKGAGGKERPGSKEEVDEDRDVDESSPQDSPPSKASPAQDGRPPQTAAREATSIPGFPAEGAIPLPVDFLSKVSTEIPASEPDGPSVGRAKGQDAPLEFTFHVEITPNVQKEQAHSEEHLGRAAFPGAPGEGPEARGPSLGEDTKEADLPEPSEKQPAAAPRGKPVSRVPQLKARMVSKSKDGTGSDDKKAKTSTRSSAKTLKNRPCLSPKHPTPGSSDPLIQPSSPAVCPEPPSSPKYVSSVTSRTGSSGAKEMKLKGADGKTKIATPRGAAPPGQKGQANATRIPAKTPPAPKTPPSSGEPPKSGDRSGYSSPGSPGTPGSRSRTPSLPTPPTREPKKVAVVRTPPKSPSSAKSRLQTAPVPMPDLKNVKSKIGSTENLKHQPGGGKVQIINKKLDLSNVQSKCGSKDNIKHVPGGGSVQIVYKPVDLSKVTSKCGSLGNIHHKPGGGQVEVKSEKLDFKDRVQSKIGSLDNITHVPGGGNKKIETHKLTFRENAKAKTDHGAEIVYKSPVVSGDTSPRHLSNVSSTGSIDMVDSPQLATLADEVSASLAKQGL Biological relevance Tau is a microtubule-associated protein that promotes microtubule assembly and stability, playing a key role in neuronal polarity, axonal transport, and cytoskeletal organization. It is centrally implicated in tauopathies — a group of neurodegenerative disorders including Alzheimer’s disease (where hyperphosphorylated tau aggregates into neurofibrillary tangles), frontotemporal dementia, progressive supranuclear palsy, and corticobasal degeneration. Accurate modeling of tau’s conformational ensemble is essential for understanding aggregation, phosphorylation effects, and therapeutic targeting. Why this is a challenging folding problem Tau is intrinsically disordered and structurally unsolved at full length: Approximately 90% of the protein is intrinsically disordered, with only transient secondary structure in microtubule-binding repeat domains No high-resolution experimental structure exists for any full-length physiological tau isoform (only fragments, aggregated filaments, or pathological paired helical filaments have been solved, e.g. PDB 5O3L, 6MZ9, 6QJQ) AlphaFold and similar tools typically assign very low pLDDT scores (<50) across most of the sequence, especially in long unstructured regions and repeat domains The protein’s extreme flexibility and aggregation propensity make ensemble prediction particularly valuable These characteristics make tau a canonical benchmark for methods targeting disordered and aggregation-prone proteins. Method: E8 Navigator The structure was generated using the E8 Navigator, a topology-driven folding engine that projects the amino acid sequence onto the exceptional Lie group E8 lattice based on physicochemical properties. Folding is performed as symmetry-constrained optimization on the E8 manifold, guided by a holographic coherence metric (Ψ) and convergence to ultra-low error states — without multiple sequence alignments, neural networks, or patterns memorized from the PDB. Results The output PDB (P10636_E8_prediction.pdb) converged with Ψ = 2.00 and very low final error(ERR: 0.00011528), producing a structured core (likely corresponding to microtubule-binding repeats) surrounded by extended, flexible regions consistent with tau’s intrinsically disordered nature. No major steric clashes were observed in the final model. Significance Tau is a paradigm example of an intrinsically disordered protein whose misfolding and aggregation drive major neurodegenerative diseases. A coherent, clash-free prediction from a purely symmetry-based method — particularly in disordered and repeat-containing regions — offers an orthogonal perspective to current AI-driven predictors. This is highly relevant for modeling tau conformational ensembles, aggregation propensity, and potential therapeutic intervention. The prediction is shared openly for visualization, alignment against experimental tau fragments (e.g. PDB 5O3L, 6MZ9), community evaluation, and comparison with other folding approaches. Files included P10636_E8_prediction.pdb — full predicted structure