DSSP 4: FAIR annotation of protein secondary structure

Protein secondary structure annotation is essential for understanding protein architecture, serving as a cornerstone for structural classification, alignment, visualization, and machine learning applications. The Define Secondary Structure of Proteins (DSSP) algorithm has long been the standard for assigning secondary structure elements such as α-helices, β-sheets, and loops in protein models. Here, we introduce DSSP version 4, which recapitulates DSSP functionality in a modern computational framework, extending also to the detection of left-handed κ-helices (Poly-Proline II helices). To align with the Findable, Accessible, Interoperable, Reusable principles, DSSP 4 adopts mmCIF as its primary input and output…