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：16078-16083
DOI：10.1073/pnas.1007144107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：During viral replication, herpesviruses package their DNA into the procapsid by means of the terminase protein complex. In human cytomegalovirus (herpesvirus 5), the terminase is composed of subunits UL89 and UL56. UL89 cleaves the long DNA concatemers into unit-length genomes of appropriate length for encapsidation. We used ESPRIT, a high-throughput screening method, to identify a soluble purifiable fragment of UL89 from a library of 18,432 randomly truncated ul89 DNA constructs. The purified protein was crystallized and its three-dimensional structure was solved. This protein corresponds to the key nuclease domain of the terminase and shows an RNase H/integrase-like fold. We demonstrate that UL89-C has the capacity to process the DNA and that this function is dependent on Mn2+ ions, two of which are located at the active site pocket. We also show that the nuclease function can be inactivated by raltegravir, a recently approved anti-AIDS drug that targets the HIV integrase.
关键词：crystal structure ; human cytomegalovirus ; DNA encapsidation ; endonuclease inhibitor ; combinatorial library
