Lemay G, Danis C
Département de Microbiologie et Immunologie, Université de Montréal, Station Centre-ville, Québec, Canada.
J Gen Virol. 1994 Nov;75 ( Pt 11):3261-6. doi: 10.1099/0022-1317-75-11-3261.
The reovirus lambda 1 protein, a major component of the inner capsid, has been shown to exhibit an affinity for dsRNA in a 'Northwestern' filter-binding assay. In the present study it was demonstrated that the protein can bind dsDNA as well as dsRNA. A bacterial expression system was used to study the protein region able to bind to nucleic acids. The amino-terminal 187 amino acids of lambda 1 were fused to the bacterial maltose-binding protein and shown to be sufficient for binding to nucleic acids. The putative zinc finger present on lambda 1 is not encompassed in this fragment of the protein. Site-directed mutagenesis also indicated that this zinc finger motif is unrelated to binding. In contrast, mutations introduced in a previously suggested nucleotide-binding motif almost completely prevented the binding. These data indicate that the amino-terminal end of lambda 1, encompassing its nucleotide-binding motif, is involved in the affinity of this protein for nucleic acids.
呼肠孤病毒λ1蛋白是内衣壳的主要成分，在“西北”滤膜结合试验中已显示出对双链RNA具有亲和力。在本研究中，证明该蛋白也能结合双链DNA和双链RNA。使用细菌表达系统研究能够与核酸结合的蛋白区域。将λ1的氨基末端187个氨基酸与细菌麦芽糖结合蛋白融合，结果表明该片段足以与核酸结合。该蛋白片段不包含λ1上假定的锌指结构。定点诱变也表明该锌指基序与结合无关。相反，在先前提出的核苷酸结合基序中引入的突变几乎完全阻止了结合。这些数据表明，λ1的氨基末端，包括其核苷酸结合基序，参与了该蛋白对核酸的亲和力。
