Department of Ribonucleoprotein Biochemistry, Institute of Bioorganic Chemistry Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
Int J Mol Sci. 2021 Jan 9;22(2):616. doi: 10.3390/ijms22020616.
Ribonuclease Dicer belongs to the family of RNase III endoribonucleases, the enzymes that specifically hydrolyze phosphodiester bonds found in double-stranded regions of RNAs. Dicer enzymes are mostly known for their essential role in the biogenesis of small regulatory RNAs. A typical Dicer-type RNase consists of a helicase domain, a domain of unknown function (DUF283), a PAZ (Piwi-Argonaute-Zwille) domain, two RNase III domains, and a double-stranded RNA binding domain; however, the domain composition of Dicers varies among species. Dicer and its homologues developed only in eukaryotes; nevertheless, the two enzymatic domains of Dicer, helicase and RNase III, display high sequence similarity to their prokaryotic orthologs. Evolutionary studies indicate that a combination of the helicase and RNase III domains in a single protein is a eukaryotic signature and is supposed to be one of the critical events that triggered the consolidation of the eukaryotic RNA interference. In this review, we provide the genetic insight into the domain organization and structure of Dicer proteins found in vertebrate and invertebrate animals, plants and fungi. We also discuss, in the context of the individual domains, domain deletion variants and partner proteins, a variety of Dicers' functions not only related to small RNA biogenesis pathways.
核糖核酸酶 Dicer 属于 RNase III 内切核酸酶家族，该酶特异性水解 RNA 双链区的磷酸二酯键。Dicer 酶主要因其在小调控 RNA 生物发生中的重要作用而闻名。典型的 Dicer 型核糖核酸酶由解旋酶结构域、功能未知结构域（DUF283）、PAZ（Piwi-Argonaute-Zwille）结构域、两个 RNase III 结构域和双链 RNA 结合结构域组成；然而，Dicers 的结构域组成在不同物种间存在差异。Dicer 及其同源物仅在真核生物中发育；然而，Dicer 的两个酶结构域，解旋酶和 RNase III，与它们的原核直系同源物具有高度的序列相似性。进化研究表明，单个蛋白中解旋酶和 RNase III 结构域的组合是真核生物的特征，并且可能是触发真核 RNA 干扰整合的关键事件之一。在这篇综述中，我们提供了关于脊椎动物和无脊椎动物、植物和真菌中发现的 Dicer 蛋白的结构域组织和结构的遗传见解。我们还讨论了各种 Dicer 功能，不仅与小 RNA 生物发生途径有关，而且还涉及到个别结构域、结构域缺失变体和伴侣蛋白的情况。
