[植物鞭毛虫长眼虫的线粒体核糖体]

[Mitochondrial ribosomes of the phytoflagellata Astasia longa].

作者信息

Gulikova O M, Zaĭtseva G N, Pakhomova M V

出版信息

Biokhimiia. 1979 Nov;44(11):2013-20.

Abstract

The physico-chemical properties of ribosomes and rRNA isolated from the mitochondria of the phytoflagellata Astasia longa were studied. It was shown that the mitochondrial ribosomes of A. longa have the sedimentation coefficient of 81S (those of the cytoplasm-82S); upon a decrease of Mg2+ concentration in the medium they dissociate into subparticles with sedimentation coefficients of 60 and 45S. The relative protein content in the mitochondrial ribosomes of A. longa is equal to 42% (rho = 1,60 g/cm3), that of cytoplasmic ribosomes-49%. The molecular weights of mitochondrial rRNA are equal to 1,05 . 10(6) and 0,71 . 10(6) and differ from those for cytoplasmic rRNA (1,32 . 10(6) and 0,94 . 10(6)). It was shown that the GC-content in mitochondrial rRNA is equal to 32,0 mol. %, that in cytoplasmic rRNA-55,9 mol. %. Thus, the mitochondrial ribosomes of A. longa differ in some of their properties from both procaryotic and eucaryotic ribosomes and are probably related to a special type of mitochondrial ribosomes.

摘要

对从植物鞭毛虫长眼虫（Astasia longa）线粒体中分离出的核糖体和rRNA的物理化学性质进行了研究。结果表明，长眼虫的线粒体核糖体沉降系数为81S（细胞质核糖体为82S）；当培养基中Mg2+浓度降低时，它们会解离成沉降系数为60和45S的亚颗粒。长眼虫线粒体核糖体中的相对蛋白质含量为42%（ρ = 1.60 g/cm3），细胞质核糖体为49%。线粒体rRNA的分子量分别为1.05×106和0.71×106，与细胞质rRNA的分子量（1.32×106和0.94×106）不同。结果表明，线粒体rRNA中的GC含量为32.0 mol.%，细胞质rRNA中为55.9 mol.%。因此，长眼虫的线粒体核糖体在某些性质上与原核和真核核糖体都不同，可能与一种特殊类型的线粒体核糖体有关。