QHELIX Program

I: About Qhelix Program

Here we present an improved computational method, Qhelix, for the calculation of the orientation angles between helices. This method provides a quantitative measure of the irregularity of helical shape, resulting in a large-scale analysis of helix geometry.The present program is capable of straightforwardly assigning the orientation direction as well as calculating the angle between two helices.


II: Getting Started (Demo)

Before using the actual Qhelix Program, a Demo version of the Qhleix program is provided. Click Demo to view Demo page

III: Test Qhelix Program on your own

From the Demo page above, you now should get a good understanding of how to run the Qhelix Program. Just like in the Demo, download any PDB file from your local computer or from the Protein Data Bank and fill in the necessary information regarding the helices and it's residues

1. File to upload
load a local PDB file from the Protein Data Bank or your computer. Click on the "Download Link" to upload an example pdb file

or Download Link
2. Number of helix domains
type the total number of helix domains and click Generate button to display additional questions on the residues as many times as the number of helices you input
3. Select a method for determining helix axes
Chou's method uses an algorithm which defines the helix axis as a least squares line calculated from all C-alpha atoms in the helix
Kahn's method uses a segment-based algorithm for defining the helical axis
Chou  Kahn
4. Click Submit to run Qhelix Program