Welcome to HeliQuest

We experienced a major server crash hosting HeliQuest. This requires a complete reinstallation of the operating system, along with necessary security updates. The screening modules are not available.
Major works will take place during the week of August 31 to September 6, resulting a server shutdown. Sorry for the inconvenience

HeliQuest calculates from an helix sequence (α-helix, 3-10 helix, 3-11 helix or π helix) its physicochemical properties and amino acid composition and uses the results to screen any databank in order to identify protein segments possessing similar features.
The server is divided into 2 interconnected modules: the sequence analysis module and the screening module for α-helix sequence and for 3-11-helix sequence.
In addition, the mutation module, (available from the sequence analysis module), allows user to mutate helices manually or automatically by genetic algorithm to create analogues with specific properties.

The module Analysis is working !This module is dedicated to characterizing helices known by the user. It determines properties as hydrophobicity, hydrophobic moment, z and amino acid composition for several helix types (α-helix, 3-10 helix, 3-11 helix or π helix).
Note 1: The link to the screening module is available only if user analyzes sequences with an 18 a.a. window (α-helix only).
Note 2: A sequence can be modified by the manual or GA-based mutation modules once analysed (α-helix only).

Screening α-Helix:Server Problem, not available !This module allows user to screen large databases in order to find sequences that have the general physico-chemical features of a target α-helix sequence.

Screening 3-11 helix: Server Problem, not available !This module allows user to screen large databases in order to find sequences that have the general physico-chemical features of a target 3-11 helix sequence.

The organization of the server is represented below with the entries and the output files.

Please cite the following reference:
Gautier R., Douguet D., Antonny B. and Drin G. HELIQUEST: a web server to screen sequences with specific α-helical properties. Bioinformatics. 2008 Sep 15;24(18):2101-2.

Comments, feedback, bugs : Please send all remarks to:

News :2011-07-05 HeliQuest version 2 with new screening module for 3-11 helix and module Analysis for several helix type (α-helix, 3-10 helix, 3-11 helix or π helix)
2011-06-24 Update of SwissProt Databases
2010-12-01 New server, more powerful and fast, Update of the SwissProt Databases
2010-02-02 Update of the SwissProt Databases
2009-04-04 Update of the SwissProt Databases
2008-09-10 Update of the SwissProt Databases
2008-07-01 HeliQuest v1.2 online