Protein sequence pattern mining with constraints

Considering the characteristics of biological sequence databases, which typically have a small alphabet, a very long length and a relative small size (several hundreds of sequences), we propose a new sequence mining algorithm (gIL). gIL was developed for linear sequence pattern mining and results from the combination of some of the most efficient techniques used in sequence and itemset mining. The algorithm exhibits a high adaptability, yielding a smooth and direct introduction of various types of features into the mining process, namely the extraction of rigid and arbitrary gap patterns. Both breadth or a depth first traversal are possible. The experimental evaluation, in synthetic and real life protein databases, has shown that our algorithm has superior performance to state-of-the art algorithms. The use of constraints has also proved to be a very useful tool to specify user interesting patternsFundação para a Ciência e a Tecnologia (FCT

Query driven sequence pattern mining

The discovery of frequent patterns present in biological sequences has a large number of applications, ranging from classification, clustering and understanding sequence structure and function. This paper presents an algorithm that discovers frequent sequence patterns (motifs) present in a query sequence in respect to a database of sequences. The query is used to guide the mining process and thus only the patterns present in the query are reported. Two main types of patterns can be identified: flexible and rigid gap patterns. The user can choose to report all or only maximal patterns. Constraints and Substitution Sets are pushed directly into the mining process. Experimental evaluation shows the efficiency of the algorithm, the usefulness and the relevance of the extracted patterns.Fundação para a Ciência e a Tecnologia (FCT