COMPUTATIONAL APPROACHES TO IDENTIFY LEUCINE ZIPPERS

The leucine zipper is a dimerization domain occurring mostly in regula tory and thus in many oncogenic proteins. The leucine repeat in the se quence has been traditionally used for identification, however with po or reliability. The coiled coil structure of a leucine zipper is requi red for dimerization and can be predicted with reasonable accuracy by existing algorithms. We exploit this fact for identification of leucin e zippers from sequence alone. We present a program, 2ZIP, which combi nes a standard coiled coil prediction algorithm with an approximate se arch for the characteristic leucine repeat. No further information fro m homologues is required for prediction. This approach improves signif icantly over existing methods, especially in that the coiled coil pred iction turns out to be highly informative and avoids large numbers of false positives. Many problems in predicting zippers or assessing pred iction results stem from wrong sequence annotations in the database.