不同生物体中线粒体亮氨酰 - tRNA顺反子的序列同源性。

Sequence homology of the mitochondrial leucyl-tRNA cistron in different organisms.

作者信息

Jakovcic S, Casey J, Rabinowitz M

出版信息

Biochemistry. 1975 May 20;14(10):2037-42. doi: 10.1021/bi00681a001.

Abstract

Sequence divergence of the mitochondrial leucytl-tRNA cistron in several eukaryotes has been examined by RNA-DNA hybridized. Rat mitochondria Leucyl-tRNA was hybridized with rat, mouse, guinea pig, monkey, chicken, and yeast mitochondrial DNAs (mtDNA) immobilized onfilters. Hybridization was carried out in 50% formamide (Tm -12degrees) or in 20% fromamide (Tm -21degrees). melting profiles of the hybrids were obtained for evaluation of the extent of base sequence micmatching. Under the more stringent hybridization conditions (50% formamide, Tm -12degrees), only mouse and quines pig mtDNAs hybridized with rat mitochondrial leucyl-tRNA. The Tm's of the heterohybrids were depressed by 2 and 9 degrees, respectively. Under less stringent hybridization conditions (Tm-21 degrees), monkey mtDNA also hybridized, and the Tm was depressed by about 15 degrees. Chicken and yeast mtDNAs did not form specific hybrids with rat mibochondrial leucyl-tRNA under these hybridization conditions. Mitochondrial leucyl-tRNA sequences in different eukaryotes appear to be conserved to a less extent than cytoplasmic rRNA, 5S RNA, or hemoglobin mRNA sequences.

摘要

通过RNA-DNA杂交检测了几种真核生物中线粒体亮氨酰-tRNA顺反子的序列差异。将大鼠线粒体亮氨酰-tRNA与固定在滤膜上的大鼠、小鼠、豚鼠、猴、鸡和酵母线粒体DNA（mtDNA）进行杂交。杂交在50%甲酰胺（Tm -12℃）或20%甲酰胺（Tm -21℃）中进行。获得杂交体的解链曲线以评估碱基序列错配程度。在更严格的杂交条件下（50%甲酰胺，Tm -12℃），只有小鼠和豚鼠的mtDNA与大鼠线粒体亮氨酰-tRNA杂交。异源杂交体的Tm分别降低了2℃和9℃。在不太严格的杂交条件下（Tm -21℃），猴的mtDNA也杂交，Tm降低了约15℃。在这些杂交条件下，鸡和酵母的mtDNA未与大鼠线粒体亮氨酰-tRNA形成特异性杂交体。不同真核生物中的线粒体亮氨酰-tRNA序列的保守程度似乎低于细胞质rRNA、5S RNA或血红蛋白mRNA序列。