We present a novel approach to managing redundancy in sequence databanks such as GenBank. We store clusters of near-identical sequences as a representative union-sequence and a set of corresponding edits to that sequence. During search, the query is compared to only the union-sequences representing each cluster; cluster members are then only reconstructed and aligned if the union-sequence achieves a sufficiently high score.
View Article and Find Full Text PDFIEEE/ACM Trans Comput Biol Bioinform
October 2007
Molecular biologists, geneticists, and other life scientists use the BLAST homology search package as their first step for discovery of information about unknown or poorly annotated genomic sequences. There are two main variants of BLAST: BLASTP for searching protein collections and BLASTN for nucleotide collections. Surprisingly, BLASTN has had very little attention; for example, the algorithms it uses do not follow those described in the 1997 BLAST paper and no exact description has been published.
View Article and Find Full Text PDFHomology search is a key tool for understanding the role, structure, and biochemical function of genomic sequences. The most popular technique for rapid homology search is BLAST, which has been in widespread use within universities, research centers, and commercial enterprises since the early 1990s. In this paper, we propose a new step in the BLAST algorithm to reduce the computational cost of searching with negligible effect on accuracy.
View Article and Find Full Text PDFBLAST is the most popular bioinformatics tool and is used to run millions of queries each day. However, evaluating such queries is slow, taking typically minutes on modern workstations. Therefore, continuing evolution of BLAST--by improving its algorithms and optimizations--is essential to improve search times in the face of exponentially increasing collection sizes.
View Article and Find Full Text PDFFast and accurate techniques for searching large genomic text collections are becoming increasingly important. While Information Retrieval is well-established for general-purpose text retrieval tasks, less is known about retrieval techniques for genomic text data. In this paper, we investigate and propose general-purpose search techniques for genomic text.
View Article and Find Full Text PDF