How to use betaturns server?

The purpose of BetaTurns server is to predict turn types I, II, IV, VIII and non-specific in a given amino acid sequence. It uses multiple alignment and secondary structure information. The turn type prediction is doen at turn level, i.e., a stretch of four residues is assigned a particular type.

About Submission Form

Input Sequence

The input sequence for prediction is a one-letter code amino acid sequence in fasta or plain text format. The name of protein/query is optional. The sequence can be pasted in the text area provided or can be uploaded through a file in the format (fasta or plain_text) specified in the form.


Shown below is the query sequence in fasta format and plain text pasted in the textarea.



The prediction method uses the PSIPRED program to have the intermediate PSI-BLAST matrices and secondary structure. The whole process is bit time consuming. The following figure shows the output of Betaturns.


The output shows the input data as submitted by the user along with the prediction results. The prediction results consists of a number of rows, first row has the query sequence(submitted by the user), second row has the secondary structure predicted by PSIPRED. PSIPRED predicts 3 states: Helix denoted by 'H', Strand denoted by 'E' and Coil denoted by 'C'. The third row has the predicted beta-turns and nonturns. The turns are denoted as t and nonturns are denoted as 'n'.

Further, the stretch of 4 residues are clssified into different turn types I, II, IV and VIII marked by roman numerals I, II, IV and VIII respectively and non-specific turn by NS.