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：2008
卷号：105
期号：39
页码：14820-14825
DOI：10.1073/pnas.0802822105
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Rifamycin antibacterial agents inhibit bacterial RNA polymerase (RNAP) by binding to a site adjacent to the RNAP active center and preventing synthesis of RNA products >2-3 nt in length. Recently, Artsimovitch et al. [(2005) Cell 122:351-363] proposed that rifamycins function by allosteric modulation of binding of Mg2+ to the RNAP active center and presented three lines of biochemical evidence consistent with this proposal. Here, we show that rifamycins do not affect the affinity of binding of Mg2+ to the RNAP active center, and we reassess the three lines of biochemical evidence, obtaining results not supportive of the proposal. We conclude that rifamycins do not function by allosteric modulation of binding of Mg2+ to the RNAP active center.
