Bayliss C D, Wilcock D, Smith G L
Sir William Dunn School of Pathology, University of Oxford, UK.
J Gen Virol. 1996 Nov;77 ( Pt 11):2827-31. doi: 10.1099/0022-1317-77-11-2827.
Four DNA-dependent ATPases were purified from vaccinia virions and tested for DNA helicase activity on two dsDNA substrates. ATPases D6R and D11L were inactive on both substrates, A18R unwound the substrate with a short 20 bp duplex region and 18R unwound both substrates. In addition, the 18R protein was stimulated to unwind longer DNA duplexes by a 25 kDa protein purified from vaccinia virions, representing the cleaved product of the L4R gene, an ssDNA binding protein. Purified recombinant 25 kDa L4R protein also stimulated 18R DNA helicase activity and maximum activity was observed only when there were < 13 nucleotides of DNA per molecule of L4R protein. The DNA helicase activity of the A18R protein was not stimulated by either recombinant 25 kDa L4R protein or by an E. coli ssDNA binding protein.
从痘苗病毒粒子中纯化出四种依赖DNA的ATP酶，并在两种双链DNA底物上测试其DNA解旋酶活性。ATP酶D6R和D11L对两种底物均无活性，A18R解开了具有短20bp双链区域的底物，而18R解开了两种底物。此外，从痘苗病毒粒子中纯化出的一种25kDa蛋白刺激18R蛋白解开更长的DNA双链，该25kDa蛋白是L4R基因的裂解产物，一种单链DNA结合蛋白。纯化的重组25kDa L4R蛋白也刺激18R DNA解旋酶活性，并且仅当每分子L4R蛋白的DNA少于13个核苷酸时才观察到最大活性。重组25kDa L4R蛋白或大肠杆菌单链DNA结合蛋白均未刺激A18R蛋白的DNA解旋酶活性。
