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：2010
卷号：107
期号：37
页码：16072-16077
DOI：10.1073/pnas.1006026107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The human mitochondrial transcription machinery generates the primers required for initiation of leading-strand DNA replication. According to one model, the 3' end of the primer is defined by transcription termination at conserved sequence block II (CSB II) in the mitochondrial DNA control region. We here demonstrate that this site-specific termination event is caused by G-quadruplex structures formed in nascent RNA upon transcription of CSB II. We also demonstrate that a poly-dT stretch downstream of CSB II has a modest stimulatory effect on the termination efficiency. The mechanism is reminiscent of Rho-independent transcription termination in prokaryotes, with the exception that a G-quadruplex structure replaces the hairpin loop formed in bacterial mRNA during transcription of terminator sequences.
