tailieunhanh - Báo cáo khoa học: Specific interaction between the classical swine fever virus NS5B protein and the viral genome

TheNS5Bproteinof the classical swine fever virus (CSFV) is the RNA-dependent RNA polymerase of the virus and is able to catalyze the viral genome replication. The 3¢ un-translated region is most likely involved in regulation of the Pestivirusgenome replication. However, little is known about the interaction between the CSFV NS5B protein and the viral used different RNA templates derived fromthe plus-strand viral genome, or theminus-strand viral genome and the CSFV NS5B protein obtained from the Escherichia coliexpression system to address this problem | Eur. J. Biochem. 271 3888-3896 2004 FEBS 2004 doi Specific interaction between the classical swine fever virus NS5B protein and the viral genome Mina Xiao1 2 Jufana Gao2. Wei Wana2. Yujina Wana2. Jun Chen2 Jiakuan Chen1 and Bo Li1 1 Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering The Institute of Biodiversity Science Fudan University Shanghai China 2College of Life and Environment Sciences Shanghai Normal University China The NS5B protein of the classical swine fever virus CSFV is the RNA-dependent RNA polymerase of the virus and is able to catalyze the viral genome replication. The 3 untranslated region is most likely involved in regulation of the Pestivirus genome replication. However little is known about the interaction between the CSFV NS5B protein and the viral genome. We used different RNA templates derived from the plus-strand viral genome or the minus-strand viral genome and the CSFV NS5B protein obtained from the Escherichia coli expression system to address this problem. We first showed that the viral NS5B protein formed a complex with the plus-strand genome through the genomic 3 UTR and that the NS5B protein was also able to bind the minus-strand 3 UTR. Moreover it was found that viral NS5B protein bound the minus-strand 3 UTR more efficiently than the plus-strand 3 UTR. Further we observed that the plus-strand 3 UTR with deletion of CCCGG or 21 continuous nucleotides at its 3 terminal had no binding activity and also lost the activity for initiation of minusstrand RNA synthesis which similarly occurred in the minus-strand 3 UTR with CATATGCTC or the 21 nucleotide fragment deleted from the 3 terminal. Therefore it is indicated that the 3 CCCGG sequence of the plus-strand 3 UTR and the 3 CATATGCtC fragment of the minusstrand are essential to in vitro synthesis of the minus-strand RNA and the plus-strand RNA respectively. The same conclusion is also appropriate for the 3 21 .