Burton Aaron S, Di Stefano Marco, Lehman Niles, Orland Henri, Micheletti Cristian
a NASA Johnson Space Center , Houston , TX , 77058 USA.
b SISSA , Via Bonomea 265, I-34014 Trieste , Italy.
RNA Biol. 2016;13(2):134-9. doi: 10.1080/15476286.2015.1132069.
Physical entanglement, and particularly knots arise spontaneously in equilibrated polymers that are sufficiently long and densely packed. Biopolymers are no exceptions: knots have long been known to occur in proteins as well as in encapsidated viral DNA. The rapidly growing number of RNA structures has recently made it possible to investigate the incidence of physical knots in this type of biomolecule, too. Strikingly, no knots have been found to date in the known RNA structures. In this Point of View Article we discuss the absence of knots in currently available RNAs and consider the reasons why knots in RNA have not yet been found, despite the expectation that they should exist in Nature. We conclude by singling out a number of RNA sequences that, based on the properties of their predicted secondary structures, are good candidates for knotted RNAs.
在足够长且紧密堆积的平衡聚合物中，物理缠结尤其是结会自发出现。生物聚合物也不例外：人们早就知道结会出现在蛋白质以及衣壳化的病毒DNA中。近年来，RNA结构数量的迅速增长使得研究这种生物分子中物理结的发生率成为可能。引人注目的是，在已知的RNA结构中迄今尚未发现结。在这篇观点文章中，我们讨论了现有RNA中不存在结的情况，并思考了尽管预计RNA中的结在自然界中应该存在，但尚未被发现的原因。最后，我们挑选出一些RNA序列，根据其预测二级结构的特性，它们是形成结的RNA的良好候选者。
