A program to characterize the geometries of helices present in proteins

HELANAL-Plus is a program to characterize overall geometry of helices from its C-alpha atom coordinates. This program can be very useful in analysis of protein secondary structure, modeling of membrane proteins, analysis of molecular dynamics runs of helices or alpha helical proteins, designed peptides containing helical motifs, etc. This web server version of HELANAL-Plus uses JmolApplet to display the helix along with its axis, in the same orientation as that in the input pdb file. Jmol is a Java applet and hence the web browser must have the Java plugin properly installed and enabled.

For single PDB file:

Please enter PDB-ID code of the protein you want to analyze:

Alternatively, you can upload a PDB format file:


For multiple PDB files: [maximum 10 files]

Enter 4 letter PDB-ID codes (seperated by comma(,)):

Alternatively, you can Upload a file containing 4 letter PDB-ID codes (one per line):
        Example File


Select Option for helix axis display

Local helix origin points
Points on the best fit 3D line / Sphere fitted to the local origin points


Helix Information: (Optional)

Upload the INPUT file containing helix start/end information or choose among STRIDE/DSSP:
[Default is the HELIX records from corresponding PDB files]



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