CARNA--alignment of RNA structure ensembles.
Due to recent algorithmic progress, tools for the gold standard of comparative RNA analysis, namely Sankoff-style simultaneous alignment and folding, are now readily applicable. Such approaches, however, compare RNAs with respect to a simultaneously predicted, single, nested consensus structure. To make multiple alignment of RNAs available in cases, where this limitation of the standard approach is critical, we introduce a web server that provides a complete and convenient interface to the RNA structure alignment tool 'CARNA'. This tool uniquely supports RNAs with multiple conserved structures per RNA and aligns pseudoknots intrinsically; these features are highly desirable for aligning riboswitches, RNAs with conserved folding pathways, or pseudoknots. We represent structural input and output information as base pair probability dot plots; this provides large flexibility in the input, ranging from fixed structures to structure ensembles, and enables immediate visual analysis of the results. In contrast to conventional Sankoff-style approaches, 'CARNA' optimizes all structural similarities in the input simultaneously, for example across an entire RNA structure ensemble. Even compared with already costly Sankoff-style alignment, 'CARNA' solves an intrinsically much harder problem by applying advanced, constraint-based, algorithmic techniques. Although 'CARNA' is specialized to the alignment of RNAs with several conserved structures, its performance on RNAs in general is on par with state-of-the-art general-purpose RNA alignment tools, as we show in a Bralibase 2.1 benchmark. The web server is freely available at http://rna.informatik.uni-freiburg.de/CARNA.
Bioinformatics Group, University of Freiburg, Georges-Köhler-Allee 106, 79110 Freiburg, Germany.
Dragos Alexandru
DA
Sorescu
Mathias
M
Möhl
Martin
M
Mann
Rolf
R
Backofen
Sebastian
S
Will
D000465:Algorithms; D020407:Internet; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry*; D016415:Sequence Alignment / Q000379:methods*; D017423:Sequence Analysis, RNA; D012984:Software
D012313:RNA