Processing of the replicase of murine coronavirus: papain-like proteinase 2 (PLP2) acts to generate p150 and p44.
Processing of the replicase of murine coronavirus: papain-like proteinase 2 (PLP2) acts to generate p150 and p44.
复制标题
鼠冠状病毒复制酶的加工：木瓜蛋白酶样蛋白酶 2 (PLP2) 产生 p150 和 p44。
DOI：
10.1007/978-1-4615-1325-4_42
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发表时间：
2001
影响因子：
--
通讯作者：
Baker,SC
中科院分区：
文献类型：
--
作者：
Kanjanahaluethai,A;Baker,SC
For Nidoviruses, proteolytic processing of a large polyprotein translated from the 5′-end of the genomic RNA is required for the maturation and assembly of the viral replicase complex. The scheme used to process the arterivirus equine arteritis virus (EAV) replicase polyprotein has been experimentally determined (reviewed in Snijder and Meulenberg, 1998). The EAV replicase polyprotein is processed by 3 distinct proteinases to generate 12 mature protein products. Polyprotein intermediates have been identified as well as major and minor processing pathways. However, the role of the intermediates and the alternate pathways remains to be investigated. For the Coronavirus mouse hepatitis virus (MHV), several laboratories are investigating the pathways used to process the replicase polyprotein. Two major processing models have been postulated and are shown in Figure 1. Studies from our laboratory showed that p150 is an intermediate to the 3C-like Proteinase (3CLpro) product p27 and that p150 likely extends to include the putative membrane-spanning protein domain 1, MPI (Schilleret al1998). In contrast, other investigators have not detected the p150 precursor and postulate that a p240 product is adjacent to p27 (Denisonet al1992; 1995 and Luet al1998). In this study, we developed a specific antiserum to the MPI domain (anti-D11) and determined that the MPI domain is indeed part of the p150 intermediate. Furthermore, we show that MHV papain-like Proteinase 2 (PLP2) is responsible for cleaving the polyprotein at the putative p150 cleavage site. These results show that PLP2 is an active enzyme.
