@conference{Gelhausen-helixLength-2019, author={Rick Gelhausen and Sebastian Will and Hofacker, Ivo L. and Rolf Backofen and Martin Raden}, title={Constraint Maximal Inter-molecular Helix Lengths within {RNA-RNA} Interaction Prediction Improves Bacterial {sRNA} Target Prediction}, booktitle={Proceedings of the 12th International Joint Conference on Biomedical Engineering Systems and Technologies - Volume 3: BIOINFORMATICS,}, year={2019}, pages={131-140}, publisher={SciTePress}, organization={INSTICC}, location = {Prague, Czech Republic}, doi={10.5220/0007689701310140}, isbn={978-989-758-353-7}, user = {mmann}, abstract= {Efficient computational tools for the identification of putative target RNAs regulated by prokaryotic sRNAs rely on thermodynamic models of RNA secondary structures. While they typically predict RNA-RNA in- teraction complexes accurately, they yield many highly-ranked false positives in target screens. One obvious source of this low specificity appears to be the disability of current secondary-structure-based models to reflect steric constraints, which nevertheless govern the kinetic formation of RNA-RNA interactions. For example, often?even thermodynamically favorable?extensions of short initial kissing hairpin interactions are kineti- cally prohibited, since this would require unwinding of intra-molecular helices as well as sterically impossible bending of the interaction helix. In consequence, the efficient prediction methods, which do not consider such effects, predict over-long helices. To increase the prediction accuracy, we devise a dynamic programming algorithm that length-restricts the runs of consecutive inter-molecular base pairs (perfect canonical stackings), which we hypothesize to implicitely model the steric and kinetic effects. The novel method is implemented by extending the state-of-the-art tool IntaRNA. Our comprehensive bacterial sRNA target prediction benchmark demonstrates significant improvements of the prediction accuracy and enables 3-4 times faster computations. These results indicate?supporting our hypothesis?that length-limitations on inter-molecular subhelices in- crease the accuracy of interaction prediction models compared to the current state-of-the-art approach.} }