PROMOTIF is a program designed to identify and analyze structural motifs in proteins. It analyzes various structural features such as secondary structure, β- and γ-turns, helical geometry and interactions, β-strands and β-sheet topology, β-bulges, β-hairpins, β-α-β units, ψ-loops, disulphide bridges, and main-chain hydrogen bonding patterns. The program generates postscript files showing examples of each motif and a summary page. It can also compare motifs in related structures, such as an ensemble of NMR structures. Protein structures are hierarchical, starting with the primary structure (amino acid sequence) that forms secondary structures like α-helices and β-strands. These secondary structures are assembled into tertiary structures. Despite the large number of known protein structures, they display a limited repertoire of patterns at the secondary, supersecondary, and tertiary levels. These patterns include secondary structural units like α- and 3₁₀ helices, β-strands, and β- and γ-turns, as well as supersecondary structures like β-hairpins, β-α-β units, and β-sheet topologies. Understanding the location and structure of these motifs is important for understanding protein relationships, evolutionary origins, and the relationship between amino acid sequence and tertiary structure. It also aids in homology modeling, ab-initio structure prediction, and novel protein design. Supersecondary structures are good candidates for nucleation sites in protein folding. Many motifs, such as β-turns and β-bulges, are functionally important as they are involved in active sites and ligand binding surfaces. PROMOTIF provides detailed analyses of these motifs, including secondary structure, β-turns, γ-turns, disulphide bridges, helices, β-strands, β-sheets, β-bulges, β-hairpins, β-α-β motifs, ψ-loops, and main-chain hydrogen bonding patterns. It generates visual representations and tables for each motif, and can be used to compare motifs in related structures. The program is flexible and can be expanded to include further motifs as standardized methods become available. It is available for academic users and can be used by researchers in X-ray crystallography and NMR spectroscopy to describe new structures.PROMOTIF is a program designed to identify and analyze structural motifs in proteins. It analyzes various structural features such as secondary structure, β- and γ-turns, helical geometry and interactions, β-strands and β-sheet topology, β-bulges, β-hairpins, β-α-β units, ψ-loops, disulphide bridges, and main-chain hydrogen bonding patterns. The program generates postscript files showing examples of each motif and a summary page. It can also compare motifs in related structures, such as an ensemble of NMR structures. Protein structures are hierarchical, starting with the primary structure (amino acid sequence) that forms secondary structures like α-helices and β-strands. These secondary structures are assembled into tertiary structures. Despite the large number of known protein structures, they display a limited repertoire of patterns at the secondary, supersecondary, and tertiary levels. These patterns include secondary structural units like α- and 3₁₀ helices, β-strands, and β- and γ-turns, as well as supersecondary structures like β-hairpins, β-α-β units, and β-sheet topologies. Understanding the location and structure of these motifs is important for understanding protein relationships, evolutionary origins, and the relationship between amino acid sequence and tertiary structure. It also aids in homology modeling, ab-initio structure prediction, and novel protein design. Supersecondary structures are good candidates for nucleation sites in protein folding. Many motifs, such as β-turns and β-bulges, are functionally important as they are involved in active sites and ligand binding surfaces. PROMOTIF provides detailed analyses of these motifs, including secondary structure, β-turns, γ-turns, disulphide bridges, helices, β-strands, β-sheets, β-bulges, β-hairpins, β-α-β motifs, ψ-loops, and main-chain hydrogen bonding patterns. It generates visual representations and tables for each motif, and can be used to compare motifs in related structures. The program is flexible and can be expanded to include further motifs as standardized methods become available. It is available for academic users and can be used by researchers in X-ray crystallography and NMR spectroscopy to describe new structures.