Catalytic activity of hammerhead ribozymes in a clay mineral environment: Implications for the RNA world
Catalytic activity of hammerhead ribozymes in a clay mineral environment: Implications for the RNA world
复制标题
DOI：
10.1016/j.gene.2006.09.002
复制
发表时间：
2007-03-01
期刊：
影响因子：
3.5
通讯作者：
Gallori, Enzo
中科院分区：
文献类型：
--
作者：
Biondi, Elisa;Branciamore, Sergio;Gallori, Enzo
假设的基于RNA的世界需要存在一个受保护的环境，其中RNA或RNA样分子可以起源并表达其生物活性。最近的研究表明，吸附/结合在粘土矿物上的RNA分子能够在降解剂存在的情况下持续存在，与周围的分子相互作用，并传输其核苷酸序列中包含的信息。在这项研究中，我们评估了具有催化活性的RNA分子在矿物环境中执行特定反应的能力。为此，我们研究了鳄梨日斑病毒 (ASBVd) 锤头核酶（单体和二聚体形式）的自裂解反应。单体转录物紧密结合在粘土矿物蒙脱土上，形成稳定的复合物，同时研究了反应混合物中粘土颗粒存在下二聚体转录物的行为。结果表明，当单体转录物吸附在粘土表面时，锤头核酶仍然具有活性，尽管其效率降低至溶液中的约20%。此外，粘土吸附分子的自裂解因5'反应产物的存在而显着增强（大约四倍）。蒙脱石存在下二聚体转录物的自裂解反应表明，矿物颗粒保护RNA分子免受非特异性降解，并将裂解动力学速率提高了约一个数量级。这些发现证实了这样的假设，即富含粘土的环境将是RNA或RNA样分子的良好栖息地。可以起源、积累并经历达尔文进化过程，从而产生地球上第一个活细胞。 (c) 2006 Elsevier B.V. 保留所有权利。
The hypothesized RNA-based world would have required the presence of a protected environment in which RNA, or an RNA-like molecule, could originate and express its biological activity.Recent studies have indicated that RNA molecules adsorbed/bound on clay minerals are able to persist in the presence of degrading agents, to interact with surrounding molecules, and to transmit the information contained in their nucleotide sequences.In this study, we assessed the ability of RNA molecules with catalytic activity to perform a specific reaction in a mineral environment. For this purpose, we investigated the self-cleavage reaction of the hammerhead ribozyme of the Avocado Sun Blotch Viroid (ASBVd), both in the monomeric and in dimeric forms. The monomeric transcript was tightly bound on the clay mineral montmorillonite to form a stable complex, while the behaviour of the dimeric transcript was studied in the presence of the clay particles in the reaction mixture.The results indicated that the hammerhead ribozyme was still active when the monomeric transcript was adsorbed on the clay surface, even though its efficiency was reduced to about 20% of that in solution. Moreover, the self-cleavage of clay-adsorbed molecule was significantly enhanced (similar to four times) by the presence of the 5' reaction product.The self-cleavage reaction of the dimeric transcript in the presence of montmorillonite indicated that the mineral particles protected the RNA molecules against aspecific degradation and increased the rate of cleavage kinetics by about one order of magnitude.These findings corroborate the hypothesis that clay-rich environments would have been a good habitat in which RNA or RNA-like molecules could originate, accumulate and undergo Darwinian evolutionary processes, leading to the first living cells on Earth. (c) 2006 Elsevier B.V. All rights reserved.