Gonzalez P, Barroso G, Labarère J
Laboratory of Molecular Genetics and Breeding of Cultivated Mushrooms, INRA-University Victor Ségalen Bordeaux 2, BP 81, 33883 Villenave d'Ornon Cédex, France.
Nucleic Acids Res. 1999 Apr 1;27(7):1754-61. doi: 10.1093/nar/27.7.1754.
The complete gene sequence and secondary structure of the mitochondrial LSU rRNA from the cultivated Basidiomycota Agrocybe aegerita was derived by chromosome walking. The A.aegerita LSU rRNA gene (13 526 nt) represents, to date, the longest described, due to the highest number of introns (eight) and the occurrence of six long nucleotidic extensions. Seven introns belong to group I, while the intronic sequence i5 constitutes the first typical group II intron reported in a fungal mitochondrial LSU rDNA. As with most fungal LSU rDNA introns reported to date, four introns (i5-i8) are distributed in domain V associated with the peptidyl-transferase activity. One intron (i1) is located in domain I, and three (i2-i4) in domain II. The introns i2-i8 possess homologies with other fungal, algal or protozoan introns located at the same position in LSU rDNAs. One of them (i6) is located at the same insertion site as most Ascomycota or algae LSU introns, suggesting a possible inheritance from a common ancestor. On the contrary, intron i1 is located at a so-far unreported insertion site. Among the six unusual nucleotide extensions, five are located in domain I and one in domain V. This is the first report of a mitochondrial LSU rRNA gene sequence and secondary structure for the whole Basidiomycota division.
通过染色体步移法获得了栽培担子菌茶树菇线粒体大亚基核糖体RNA（LSU rRNA）的完整基因序列和二级结构。茶树菇LSU rRNA基因（13526个核苷酸）是迄今为止所描述的最长的基因，这是由于其内含子数量最多（8个）以及出现了6个长核苷酸延伸。7个内含子属于I组，而内含子序列i5构成了在真菌线粒体LSU rDNA中报道的第一个典型II组内含子。与迄今为止报道的大多数真菌LSU rDNA内含子一样，4个内含子（i5-i8）分布在与肽基转移酶活性相关的结构域V中。一个内含子（i1）位于结构域I中，3个（i2-i4）位于结构域II中。内含子i2-i8与LSU rDNAs中位于相同位置的其他真菌、藻类或原生动物内含子具有同源性。其中一个（i6）位于与大多数子囊菌或藻类LSU内含子相同的插入位点，这表明可能继承自共同祖先。相反，内含子i1位于一个迄今为止未报道的插入位点。在6个异常核苷酸延伸中，5个位于结构域I中，1个位于结构域V中。这是关于整个担子菌门线粒体LSU rRNA基因序列和二级结构的首次报道。
