Golovko Anna, Sitbon Folke, Tillberg Elisabeth, Nicander Björn
Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala.
Plant Mol Biol. 2002 May;49(2):161-9. doi: 10.1023/a:1014958816241.
The tRNA of most organisms contain modified adenines called cytokinins. Situated next to the anticodon, they have been shown to influence translational fidelity and efficiency. The enzyme that synthesizes cytokinins on pre-tRNA, tRNA isopentenyltransferase (EC 2.5.1.8), has been studied in micro-organisms like Escherichia coli and SaccharomYces cerevisiae, and the corresponding genes have been cloned. We here report the first cloning and functional characterization of a homologous gene from a plant, Arabidopsis thaliana. Expression in S. cerevisiae showed that the gene can complement the anti-suppressor phenotype of a mutant that lacks MOD5, the intrinsic tRNA isopentenyltransferase gene. This was accompanied by the reintroduction of isopentenyladenosine in the tRNA. The Arabidopsis gene is constitutively expressed in seedling tissues.
大多数生物体的转运RNA（tRNA）含有被称为细胞分裂素的修饰腺嘌呤。它们位于反密码子旁边，已被证明会影响翻译保真度和效率。在诸如大肠杆菌和酿酒酵母等微生物中，对在pre-tRNA上合成细胞分裂素的酶——tRNA异戊烯基转移酶（EC 2.5.1.8）进行了研究，并且相应的基因已被克隆。我们在此报告了来自植物拟南芥的一个同源基因的首次克隆及其功能特性。在酿酒酵母中的表达表明，该基因可以弥补缺乏固有tRNA异戊烯基转移酶基因MOD5的突变体的抗抑制表型。这伴随着tRNA中异戊烯基腺苷的重新引入。拟南芥基因在幼苗组织中组成型表达。
