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:1980
卷号:77
期号:6
页码:3365-3368
DOI:10.1073/pnas.77.6.3365
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Two Drosophila tRNALys genes with identical coding sequences were shown to transcribe with very different efficiences in nuclear extracts from Xenopus oocytes. The use of recombinant plasmids in which the 5'-flanking sequences of these genes were either "switched" or replaced by defined pBR322 sequences revealed two control regions for tRNA gene transcription. An internal control region comprising the mature tRNA coding sequence (and possibly its 3'-flanking sequences) is sufficient for transcription initiation, and an external control region comprising the 5'-flanking sequences represses this transcription. All transcripts have short leader sequences. Altered precursor tRNAs transcribed from truncated tRNALys genes (missing a single base pair in the acceptor stem) are not processed well in vitro.