SECONDARY METHYLATION OF YEAST RIBOSOMAL PRECURSOR RNA
SECONDARY METHYLATION OF YEAST RIBOSOMAL PRECURSOR RNA
复制标题
DOI：
10.1111/j.1432-1033.1977.tb11531.x
复制
发表时间：
1977-01-01
期刊：
影响因子：
--
通讯作者：
PLANTA, RJ
中科院分区：
文献类型：
--
作者：
BRAND, RC;KLOOTWIJK, J;PLANTA, RJ
通过对来自不同前体的甲基化寡核苷酸的指纹分析，研究了啤酒酵母核糖体前体RNA(Pre-rRNA)的核糖体序列甲基化的时间。在26-S核糖核酸的37个核糖基团和6个碱甲基中，在26-S和17-S核糖核酸的共同前体37-S核糖核酸中尚不存在2个碱基甲基化的核苷M3U和双甲基化序列Um-GM-.PSI。将这些甲基引入核糖体序列是在29-S前rRNA水平上进行的，它是26-S rRNA的直接前体。从17-S核糖核酸中发现的18个核糖甲基化和6个碱基甲基化的核苷中，后者组(1个拷贝的m7G，**图形**。序列和高度修饰的甲基化核苷‘’mX‘’)在37-S前rRNA中完全缺失。M7G的甲基被引入到核内17-S rRNA的直接前体18-S前rRNA中。**图形**。序列甲基化后将18-S前rRNA分子运输到细胞质中，最后成熟为17-S rRNA。
The timing of methylation of the ribosomal sequences of ribosomal precursor RNA (pre-rRNA) from the yeast Saccharomyces carlsbergensis was investigated by fingerprint analysis of the methylated oligonucleotides derived from the various precursors. From 37 ribose and 6 base-methyl groups found in 26-S rRNA, the 2 copies of the base methylated nucleoside m3U as well as the doubly methylated sequence Um-Gm-.PSI. are not yet present in 37-S RNA, the predominant common precursor of 26-S and 17-S rRNA. Introduction of these methyl groups into the ribosomal sequences takes place at the level of 29-S pre-rRNA which is the immediate precursor to 26-S rRNA. From 18 ribose-methylated and 6 base-methylated nucleosides found in 17-S rRNA, the latter group (1 copy of m7G, the .**GRAPHIC**. sequence and the hypermodified methylated nucleoside ''mX'') is completely missing in 37-S pre-rRNA. The methyl group of m7G is introduced into 18-S pre-rRNA, the direct precursor of 17-S rRNA, in the nucleus. The .**GRAPHIC**. sequence is methylated after transport of the 18-S pre-rRNA molecules to the cytoplasm prior to the final maturation into 17-S rRNA.