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：4
页码：1041-1045
DOI：10.1073/pnas.70.4.1041
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The nucleotide sequence G-T-{Psi}-C-G(A)- has previously been found in every tRNA of known sequence that is active in protein biosynthesis. An exception to this generalization is the recently sequenced initiator tRNA from yeast cytoplasm. It is now reported that cytoplasmic initiator tRNAs from wheat germ, rabbit liver, and sheep mammary gland also lack the G-T-{Psi}-C-G(A)- sequence. Thus: (i) nucleoside composition analyses show the absence of T in all these tRNAs; (ii) analyses of oligonucleotide fragments produced by T1 ribonuclease show the absence not only of the T-{Psi}-C-G(A)- sequence, but also of U-{Psi}-C-G(A)- or U-U-C-G(A)- sequences in such digests. The absence of G-T-{Psi}-C-G(A)- in the eukaryotic cytoplasmic initator tRNAs is, therefore, not simply due to lack of enzymatic modification of U to T.
