Predicted regions from ANCHOR and IUPRED

Since LCRs are commonly associated with intrinsically disorder regions in protein sequences, having such information readily available can be very helpful. LCR-eXXXplorer utilizes IUPRED and ANCHOR, two algorithms that rely on pairwise energy estimation to predict disorder and binding regions respectively.

IUPRED (http://iupred.enzim.hu/) is designed to predict intrinsically disordered protein segments that are at least 30 residues long. For each residue in the protein sequence a disorder probability is given; residues with values greater than 0.5 are predicted to be disordered. These scores are displayed as a line graph in LCR-eXXXplorer; values greater than 0.5 are coloured gold while the rest are coloured cyan. IUPRED is also used to predict putative ordered (globular) regions. Neighbouring globular regions are merged together and if the final one is longer than 30 residues it is displayed as a cyan rectangle, just above the line graph.

ANCHOR (http://anchor.enzim.hu/) scores on the other hand show the probability of each residue to be a part of a disordered binding region. For a region to be predicted as a disordered binding region (blue rectangles) a score higher than 0.5 is required (the darker the rectangle color, the higher the ANCHOR score). Furthermore, predicted bidning regions are filtered out (green rectangles) if their length is shorter than six residues long.

Relevant references:
  • IUPred: web server for the prediction of intrinsically unstructured regions of proteins based on estimated energy content. Zsuzsanna Dosztanyi, Veronika Csizmok, Peter Tompa and Istvan Simon. (2009). Bioinformatics 21, 3433-3434. (PMID: 15955779)
  • ANCHOR: web server for predicting protein binding regions in disordered proteins. Zsuzsanna Dosztanyi, Balint Meszaros and Istvan Simon. (2005). Bioinformatics 25(20): 2745-2746. (PMID: 19717576)