Coronavirus genome: prediction of putative functional domains in the non-structural polyprotein by comparative amino acid sequence analysis.
Coronavirus genome: prediction of putative functional domains in the non-structural polyprotein by comparative amino acid sequence analysis.
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DOI：
10.1093/nar/17.12.4847
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发表时间：
1989-06-26
影响因子：
14.9
通讯作者：
Blinov VM
中科院分区：
文献类型：
--
作者：
Gorbalenya AE;Koonin EV;Donchenko AP;Blinov VM
用计算机辅助方法比较了传染性支气管炎病毒（IBV）的两个巨大非结构多聚蛋白（F1和F2）的氨基酸序列与其它一些正链RNA病毒和细胞蛋白的序列。通过这种方法，并置推定的RNA依赖性RNA聚合酶，核酸结合（“手指”样）和RNA解旋酶结构域中确定的F2。这些结构域可能共同构成了冠状病毒依赖引物的转录、复制和重组所涉及的蛋白复合物的核心。在F1中，两个半胱氨酸蛋白酶样结构域和一个生长因子样结构域被发现。IBV的推定蛋白酶之一类似于小核糖核酸病毒的3C蛋白酶和豇豆花叶病毒和马铃薯Y病毒的相关酶。在IBV F1和F2序列中寻找与后者蛋白酶切割位点相似的位点，并与周围序列片段进行比较，发现13个可能被冠状病毒3C样蛋白酶切割的二肽Q/S（G）。在此基础上，对IBV非结构多聚蛋白的功能组织和表达策略提出了部分设想。这意味着，尽管冠状病毒与其他正链RNA病毒（特别是马铃薯Y病毒）总体相似，但冠状病毒仍具有许多独特的结构和功能特征。
Amino acid sequences of 2 giant non-structural polyproteins (F1 and F2) of infectious bronchitis virus (IBV), a member of Coronaviridae, were compared, by computer-assisted methods, to sequences of a number of other positive strand RNA viral and cellular proteins. By this approach, juxtaposed putative RNA-dependent RNA polymerase, nucleic acid binding ("finger"-like) and RNA helicase domains were identified in F2. Together, these domains might constitute the core of the protein complex involved in the primer-dependent transcription, replication and recombination of coronaviruses. In F1, two cysteine protease-like domains and a growth factor-like one were revealed. One of the putative proteases of IBV is similar to 3C proteases of picornaviruses and related enzymes of como- nepo- and potyviruses. Search of IBV F1 and F2 sequences for sites similar to those cleaved by the latter proteases and intercomparison of the surrounding sequence stretches revealed 13 dipeptides Q/S(G) which are probably cleaved by the coronavirus 3C-like protease. Based on these observations, a partial tentative scheme for the functional organization and expression strategy of the non-structural polyproteins of IBV was proposed. It implies that, despite the general similarity to other positive strand RNA viruses, and particularly to potyviruses, coronaviruses possess a number of unique structural and functional features.