IRIS: Internal Repeat Identification System

Protein repeats are considered as a significant role in protein function analysis and structural evolution. About 25% of all proteins contain repeat structures for eukaryote species and most of them do not have the resolved structural information yet. Therefore, this study aimed to identify internal repeats from soely protein sequences information. Traditional detection methods exploited amino acid sequence alignment to detect protein repeats from protein sequences, but the performance was satisfied limited to high sequence similarity. In this study, a novel method was proposed based on the predicted secondary structure element information. Sequences were firstly transformed into Length Encoded Secondary Structure (LESS) profiles and followed by autocorrelation analyses. From the primary experimental results, the developed Internal Repeat Identification System (IRIS) can successfully identify internal repeats from some well-known preotein structures, such as Tata-box Binding protein of Sulfolobus acidocaldarius and porcine ribonuclease inhibitor complexed with the ribonuclease.