Chercher Où Une Deviation Existe Sûrement.

This page briefly describes the use of COUDES webserver. You can go to:

  1. Principle
  2. Quick Help
  3. Detailed Help
  4. Note
  5. References


COUDES is a web-server that makes beta-turns prediction as well as their type. The basic principle is to predict first secondary structures with an accurate method such as PSIPRED (Jones, 1999), and to predict beta-turns within (almost) coil regions. The prediction within coil is done by using propensities weighted by scores coming from position specific scoring matrices (PSSMs) generated by PSI-BLAST (Altschul & al., 1997). For each predicted beta-turn, its type is then predicted using solely propensities.

For further details please see Fuchs & Alix (2005).

Quick Help

Predicting beta-turns through COUDES webserver is pretty easy. Go to the query page; it should look like the following:

The only thing you have to do is to paste your sequence in the large textarea (in plain or fasta format), and click on the button "Predict Turns!". All option values are set in order to get the best results in terms of well balanced under and over-prediction (see Fuchs & Alix (2004)).

For further details please see Fuchs & Alix (2005).

Detailed Help

Here is a brief explanation of each element in the Web-Page:

For further details please see Fuchs & Alix (2005).


May 2015: COUDES has been unavailable for a few months, sorry for the inconvenience. The service is now back and fully implemented within the Mobyle platform. The nr database of protein sequences that has been used to test COUDES in the original publication (DOI: 10.1002/prot.20461) is no longer avalaible. Thus you might get slightly different results compared to the original version published in 2005 (and so does for the psipred prediction). We now use uniref90 (version 2006-04-27), more recent versions containing many more sequences are not worth the extra computational cost.


Go to the query page

Go to the additional data page