Lu Y B, Ratnakar P V, Mohanty B K, Bastia D
Department of Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
Proc Natl Acad Sci U S A. 1996 Nov 12;93(23):12902-7. doi: 10.1073/pnas.93.23.12902.
The primase DnaG of Escherichia coli requires the participation of the replicative helicase DnaB for optimal synthesis of primer RNA for lagging strand replication. However, previous studies had not determined whether the activation of the primase or its loading on the template was accomplished by a helicase-mediated structural alteration of the single-stranded DNA or by a direct physical interaction between the DnaB and the DnaG proteins. In this paper we present evidence supporting direct interaction between the two proteins. We have mapped the surfaces of interaction on both DnaG and DnaB and show further that mutations that reduce the physical interation also cause a significant reduction in primer synthesis. Thus, the physical interaction reported here appears to be physiologically significant.
大肠杆菌的引发酶DnaG需要复制解旋酶DnaB的参与，才能为滞后链复制最佳地合成引物RNA。然而，先前的研究尚未确定引发酶的激活或其在模板上的装载是通过解旋酶介导的单链DNA结构改变来完成，还是通过DnaB与DnaG蛋白之间的直接物理相互作用来完成。在本文中，我们提供了支持这两种蛋白直接相互作用的证据。我们已经绘制了DnaG和DnaB上的相互作用表面，并进一步表明，减少物理相互作用的突变也会导致引物合成显著减少。因此，本文报道的物理相互作用似乎具有生理意义。
