DPCexplorer: A Django Web Application for Interactive Exploration of DPCfam and DPCstruct Protein Domain Classifications

DPCexplorer is an open-source Django 6.0.1 web application that provides interactive browser-based access to two large, unsupervised protein domain family classifications: DPCfam (81,384 sequence-based metaclusters derived from UniRef50 via BLASTp and Density Peak Clustering) and DPCstruct (28,246 structure-based metaclusters derived from the AlphaFold Database via Foldseek and Density Peak Clustering). Raw archives were preprocessed on the ORFEO HPC cluster and loaded into a PostgreSQL 16.11 database optimized with B-Tree, GIN trigram, and functional indexes for fast lookup across millions of protein assignments. Built on the Model-View-Template pattern, the platform supports four query types (DPCfam MCID, DPCstruct MCID, Pfam ID, UniProt accession), serves downloadable biological files (FASTA, MSA, HMM, PDB), renders a per-protein domain-architecture diagram, and embeds an interactive 3D molecular viewer powered by PDBe-Molstar for DPCstruct metaclusters. The platform is designed in alignment with FAIR Principles for Research Software (FAIR4RS) and is fully reproducible from the associated GitHub repository and Zenodo data deposit (https://doi.org/10.5281/zenodo.20159208).