Whitehead S S, Hruby D E
Department of Microbiology, Oregon State University, Corvallis 97331-3804.
J Virol. 1994 Nov;68(11):7603-8. doi: 10.1128/JVI.68.11.7603-7608.1994.
Vaccinia virus maturation into infectious particles appears to be dependent on the proteolytic processing of at least five viral proteins, each containing a conserved AGX cleavage motif and each requiring proper association with the previrion particle. To identify the responsible proteinase, a transcriptionally controlled trans-processing assay was developed to monitor cleavage at the permissive AGS site of the P25K core protein precursor. This assay led to the putative identification of a VV proteinase encoded by open reading frame G1L. The predicted protein contains an HXXEH sequence which is a direct inversion of the active site consensus sequence present in thermolysin and other metalloendopeptidases. Site-directed mutation of this consensus sequence suggests that the G1L protein may be a novel, virus-encoded metalloendoproteinase, although confirmation of this activity must await the development of a suitable cell-free processing assay.
痘苗病毒成熟为感染性颗粒似乎依赖于至少五种病毒蛋白的蛋白水解加工，每种蛋白都含有保守的AGX切割基序，并且每种蛋白都需要与病毒前体颗粒正确结合。为了鉴定负责的蛋白酶，开发了一种转录控制的转加工试验，以监测P25K核心蛋白前体在允许的AGS位点的切割。该试验导致推定鉴定出由开放阅读框G1L编码的痘苗病毒蛋白酶。预测的蛋白包含一个HXXEH序列，该序列是嗜热菌蛋白酶和其他金属内肽酶中存在的活性位点共有序列的直接反转。该共有序列的定点突变表明，G1L蛋白可能是一种新型的、病毒编码的金属内蛋白酶，尽管这种活性的确认必须等待合适的无细胞加工试验的开发。
