FoldHandedness

FoldHandedness analyzes and characterizes the structural properties of α-helices within protein chains using PDB-derived coordinates and DSSP helix definitions to compute interhelix angles and handedness.

Key Features:

• Helix Region Definition: Defines α-helix regions from Protein Data Bank (PDB) files using the latest version of the DSSP program for helix assignment.
• Handedness Determination: Determines the handedness for any chosen set of three helices to assess spatial chirality of helical arrangements.
• Angle and Sign Calculation: Computes the angle and the sign between pairs of selected helices to quantify their relative orientations, applicable to large proteins and complexes with DNA or RNA.

Scientific Applications:

• Analysis of large proteins and protein–nucleic acid complexes: Provides insights into spatial arrangement of α-helices that can affect mechanisms of action, stability, and interaction dynamics in assemblies involving DNA or RNA.
• Structural studies for drug design, molecular biology, and bioinformatics: Facilitates exploration of how specific helical structural features contribute to biological processes and functional hypotheses.

Methodology:

Uses PDB files as input, applies the latest DSSP program to define helix regions, and computes geometric relationships—angles, signs, and handedness—between selected helices, including determination for sets of three helices.