PARTIAL-PURIFICATION AND PROPERTIES OF RETICULOCYTE GUANYLATING ENZYME
PARTIAL-PURIFICATION AND PROPERTIES OF RETICULOCYTE GUANYLATING ENZYME
复制标题
DOI：
10.1016/0005-2787(76)90312-9
复制
发表时间：
1976-01-01
期刊：
影响因子：
--
通讯作者：
FARKAS, WR
中科院分区：
文献类型：
--
作者：
DUBRUL, EF;FARKAS, WR
The guanylating enzyme which catalyzes the insertion of a guanine residue into 1 of the isoaccepting tRNAHis of rabbit reticulocytes was purified .apprx. 100-fold. It is free of nuclease activity. The enzyme does not catalyze the replacement of inserted radioactive guanine by unlabeled guanine, indicating that the reaction is irreversible. The tRNAHis of reticulocytes was separated into 3 isoacceptors. The last histidyl-tRNA to elute from RPC-5 columns was the product of the guanylation reaction. The same late-eluting peak also contains the substrate for the guanylating enzyme, indicating that the guanine insertion reaction is chromatographically silent. The isoaccepting tRNAHis that is the substrate for the guanylating enzyme does not contain the hypermodified base known as Q. It is the other major reticulocyte tRNAHis that contains Q, showing that, at least in the reticulocyte, the role of the guanylating enzyme is not the conversion of the Q form of tRNA to the homogeneic G form. The purified enzyme does not insert any base other than guanine into tRNA.
