Shepard D A, Ehnstrom J G, Skinner P J, Schiff L A
Department of Microbiology, University of Minnesota, Minneapolis 55455, USA.
J Virol. 1996 Mar;70(3):2065-8. doi: 10.1128/JVI.70.3.2065-2068.1996.
Reovirus capsid protein delta 3 binds both double-stranded RNA (dsRNA) and zinc. Previous studies have revealed that the amino-terminal zinc finger is not required for the ability of delta 3 to bind dsRNA. We expressed wild-type and mutant delta 3 molecules by in vitro transcription/translation to evaluate the importance of the zinc finger for other functions of delta 3. delta 3 molecules with mutations in the zinc finger did not form complexes with capsid protein mu 1 but bound dsRNA more efficiently than wild-type delta 3 did. In contrast, a dsRNA-binding mutant was unimpaired in its ability to associate with mu 1. Studies with delta 3 fragments support these findings and indicate that sequences critical for delta 3's interaction with mu 1 lie in the amino terminus of the molecule. Our finding that mu 1 and dsRNA do not compete for identical binding sites on delta 3 has implications for its function as a translational regulator in infected cells.
呼肠孤病毒衣壳蛋白δ3能结合双链RNA（dsRNA）和锌。先前的研究表明，δ3结合dsRNA的能力并不需要氨基末端的锌指结构。我们通过体外转录/翻译来表达野生型和突变型δ3分子，以评估锌指结构对δ3其他功能的重要性。锌指结构发生突变的δ3分子不能与衣壳蛋白μ1形成复合物，但与野生型δ3相比，其结合dsRNA的效率更高。相反，一个dsRNA结合突变体与μ1结合的能力并未受损。对δ3片段的研究支持了这些发现，并表明δ3与μ1相互作用的关键序列位于该分子的氨基末端。我们发现μ1和dsRNA不会竞争δ3上相同的结合位点，这对其在受感染细胞中作为翻译调节因子的功能具有重要意义。
