期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1973
卷号：70
期号：12
页码：3626-3630
DOI：10.1073/pnas.70.12.3626
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Certain nucleotides in precursor RNA of tRNATyr of Escherichia coli were modified in vitro with a preparation of partially purified E. coli enzyme containing ribothymidine- and pseudouridine-forming activity. The only nucleotides modified in vitro are the same as those found modified in mature tRNA. The best substrate for these modifying enzymes is the RNase P cleavage product of the precursor RNA, which contains the mature tRNA sequence. Of the two pseudouridines found in mature tRNA, one (in the T{Psi}C sequence) can be formed in intact precursor RNA. The other (in the anticodon stem) can only be formed in the cleaved precursor RNA. The presence of modified nucleotides in the precursor RNA does not enhance its rate of cleavage by RNase P.
