Title
Query-Dependent Banding (Qdb) For Faster Rna Similarity Searches
Abstract
When searching sequence databases for RNAs, it is desirable to score both primary sequence and RNA secondary structure similarity. Covariance models (CMs) are probabilistic models well-suited for RNA similarity search applications. However, the computational complexity of CM dynamic programming alignment algorithms has limited their practical application. Here we describe an acceleration method called query-dependent banding (QDB), which uses the probabilistic query CM to precalculate regions of the dynamic programming lattice that have negligible probability, independently of the target database. We have implemented QDB in the freely available Infernal software package. QDB reduces the average case time complexity of CM alignment from LN2.4 to LN1.3 for a query RNA of N residues and a target database of L residues, resulting in a 4-fold speedup for typical RNA queries. Combined with other improvements to Infernal, including informative mixture Dirichlet priors on model parameters, benchmarks also show increased sensitivity and specificity resulting from improved parameterization.
Year
DOI
Venue
2007
10.1371/journal.pcbi.0030056
PLOS COMPUTATIONAL BIOLOGY
Field
DocType
Volume
Dynamic programming,Rfam,Computer science,Probabilistic logic,Bioinformatics,Time complexity,Nearest neighbor search,Nucleic acid secondary structure,Computational complexity theory,Speedup
Journal
3
Issue
ISSN
Citations 
3
1553-734X
42
PageRank 
References 
Authors
3.28
13
2
Name
Order
Citations
PageRank
Eric P. Nawrocki134723.75
Sean R Eddy262121176.92