RNA-LEGO: Combinatorial Design of Pseudoknot RNA
نویسندگان
چکیده
In this paper we enumerate k-noncrossing RNA pseudoknot structures with given minimum stack-length. We show that the numbers of k-noncrossing structures without isolated base pairs are significantly smaller than the number of all k-noncrossing structures. In particular we prove that the number of 3and 4-noncrossing RNA structures with stack-length ≥ 2 is for large n given by 311.2470 4! n(n−1)...(n−4) 2.5881 and 1.217 · 107n 21 2 3.0382, respectively. We furthermore show that for k-noncrossing RNA structures the drop in exponential growth rates between the number of all structures and the number of all structures with stack-size ≥ 2 increases significantly. Our results are of importance for prediction algorithms for pseudoknotRNA and provide evidence that there exist neutral networks of RNA pseudoknot structures.
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