Barish Robert D, Schulman Rebecca, Rothemund Paul W K, Winfree Erik
California Institute of Technology, Pasadena, CA 91125, USA.
Proc Natl Acad Sci U S A. 2009 Apr 14;106(15):6054-9. doi: 10.1073/pnas.0808736106. Epub 2009 Mar 24.
Self-assembly creates natural mineral, chemical, and biological structures of great complexity. Often, the same starting materials have the potential to form an infinite variety of distinct structures; information in a seed molecule can determine which form is grown as well as where and when. These phenomena can be exploited to program the growth of complex supramolecular structures, as demonstrated by the algorithmic self-assembly of DNA tiles. However, the lack of effective seeds has limited the reliability and yield of algorithmic crystals. Here, we present a programmable DNA origami seed that can display up to 32 distinct binding sites and demonstrate the use of seeds to nucleate three types of algorithmic crystals. In the simplest case, the starting materials are a set of tiles that can form crystalline ribbons of any width; the seed directs assembly of a chosen width with >90% yield. Increased structural diversity is obtained by using tiles that copy a binary string from layer to layer; the seed specifies the initial string and triggers growth under near-optimal conditions where the bit copying error rate is <0.2%. Increased structural complexity is achieved by using tiles that generate a binary counting pattern; the seed specifies the initial value for the counter. Self-assembly proceeds in a one-pot annealing reaction involving up to 300 DNA strands containing >17 kb of sequence information. In sum, this work demonstrates how DNA origami seeds enable the easy, high-yield, low-error-rate growth of algorithmic crystals as a route toward programmable bottom-up fabrication.
自组装可形成极其复杂的天然矿物、化学和生物结构。通常,相同的起始材料有可能形成无限多种不同的结构;种子分子中的信息可以决定生长出哪种形式的结构以及生长的位置和时间。正如DNA瓦片的算法自组装所证明的那样,这些现象可用于对复杂超分子结构的生长进行编程。然而,缺乏有效的种子限制了算法晶体的可靠性和产量。在此,我们展示了一种可编程的DNA折纸种子,它可以展示多达32个不同的结合位点,并演示了使用种子使三种类型的算法晶体成核。在最简单的情况下,起始材料是一组能够形成任意宽度晶体带的瓦片;种子引导组装出选定宽度的晶体带,产率超过90%。通过使用能在层与层之间复制二进制字符串的瓦片可获得更高的结构多样性;种子指定初始字符串并在近最优条件下触发生长,此时位复制错误率小于0.2%。通过使用能生成二进制计数模式的瓦片可实现更高的结构复杂性;种子指定计数器的初始值。自组装在一锅退火反应中进行,该反应涉及多达300条DNA链,包含超过17 kb的序列信息。总之,这项工作展示了DNA折纸种子如何实现算法晶体的简便、高产、低错误率生长,作为一种通向可编程自下而上制造的途径。