Center for Theoretical Biological Physics, University of California at San Diego, La Jolla, CA 92037, USA.
Proc Natl Acad Sci U S A. 2012 Jun 26;109(26):E1715-23. doi: 10.1073/pnas.1205918109. Epub 2012 Jun 8.
While analyzing all available protein structures for the presence of knots and slipknots, we detected a strict conservation of complex knotting patterns within and between several protein families despite their large sequence divergence. Because protein folding pathways leading to knotted native protein structures are slower and less efficient than those leading to unknotted proteins with similar size and sequence, the strict conservation of the knotting patterns indicates an important physiological role of knots and slipknots in these proteins. Although little is known about the functional role of knots, recent studies have demonstrated a protein-stabilizing ability of knots and slipknots. Some of the conserved knotting patterns occur in proteins forming transmembrane channels where the slipknot loop seems to strap together the transmembrane helices forming the channel.
在分析所有可用的蛋白质结构中是否存在纽结和滑纽结时，尽管它们的序列差异很大，但我们在几个蛋白质家族内和之间发现了复杂纽结模式的严格保守性。由于导致纽结天然蛋白质结构的蛋白质折叠途径比导致具有相似大小和序列的无纽结蛋白质的折叠途径更慢且效率更低，因此纽结模式的严格保守性表明纽结和滑纽结在这些蛋白质中具有重要的生理作用。尽管关于纽结的功能作用知之甚少，但最近的研究表明纽结和滑纽结具有稳定蛋白质的能力。一些保守的纽结模式出现在形成跨膜通道的蛋白质中，其中滑纽结环似乎将形成通道的跨膜螺旋绑在一起。
