Domain swapping reveals that the C- and N-terminal domains of DnaG and DnaB, respectively, are functional homologues.
Domain swapping reveals that the C- and N-terminal domains of DnaG and DnaB, respectively, are functional homologues.
复制标题
DOI：
10.1111/j.1365-2958.2007.05617.x
复制
发表时间：
2007-03
影响因子：
3.6
通讯作者：
Soultanas P
中科院分区：
文献类型：
--
作者：
Chintakayala K;Larson MA;Grainger WH;Scott DJ;Griep MA;Hinrichs SH;Soultanas P
细菌引发酶（DnaG）-解旋酶（DnaB）相互作用由DnaG的C-末端结构域（p16）和连接DnaB的N-和C-末端结构域（分别为p17和p33）的接头介导。晶体和核磁共振结构的p16从大肠杆菌和嗜热脂肪芽孢杆菌DnaG蛋白揭示了一个独特的结构同源性与p17，尽管缺乏氨基酸序列的相似性。其功能意义尚不清楚。在这里，我们采用了“结构域交换”的方法来取代p17与其结构同源p16创建嵌合体。p33单独水解ATP，但不显示解旋酶活性。将p16（p16-p33）或DnaG（G-p33）融合到p33的N-末端产生具有部分恢复的解旋酶活性的嵌合体。这两种嵌合体都不与DnaG相互作用。p16-p33嵌合体形成六聚体，而G-p33组装成四聚体。G-p33和DnaB形成的混合寡聚体的ATP酶活性高于DnaB/DnaG复合物，解旋酶活性高于DnaB和G-p33的活性之和，但低于DnaB/DnaG复合物。我们的综合数据提供了直接的证据表明，p16和p17不仅是结构上的，而且功能上的同源物，尽管它们的氨基酸组成差异可能会影响它们的确切作用。
The bacterial primase (DnaG)–helicase (DnaB) interaction is mediated by the C-terminal domain of DnaG (p16) and a linker that joins the N- and C-terminal domains (p17 and p33 respectively) of DnaB. The crystal and nuclear magnetic resonance structures of p16 from Escherichia coli and Bacillus stearothermophilus DnaG proteins revealed a unique structural homology with p17, despite the lack of amino acid sequence similarity. The functional significance of this is not clear. Here, we have employed a ‘domain swapping’ approach to replace p17 with its structural homologue p16 to create chimeras. p33 alone hydrolyses ATP but exhibits no helicase activity. Fusing p16 (p16-p33) or DnaG (G-p33) to the N-terminus of p33 produced chimeras with partially restored helicase activities. Neither chimera interacted with DnaG. The p16-p33 chimera formed hexamers while G-p33 assembled into tetramers. Furthermore, G-p33 and DnaB formed mixed oligomers with ATPase activity better than that of the DnaB/DnaG complex and helicase activity better than the sum of the individual DnaB and G-p33 activities but worse than that of the DnaB/DnaG complex. Our combined data provide direct evidence that p16 and p17 are not only structural but also functional homologues, albeit their amino acid composition differences are likely to influence their precise roles.
登录
查看更多内容
影响因子：
14.9
作者：
Soultanas, P;Wigley, DB
通讯作者：
Wigley, DB
影响因子：
64.5
作者：
Yuzhakov, A;Kelman, Z;O'Donnell, M
通讯作者：
O'Donnell, M
DOI：
10.1016/s0167-4781(99)00024-x
发表时间：
1999-03-19
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA-GENE STRUCTURE AND EXPRESSION
影响因子：
--
作者：
Bird, LE;Wigley, DB
通讯作者：
Wigley, DB
影响因子：
64.8
作者：
Lee, JB;Hite, RK;van Oijen, AM
通讯作者：
van Oijen, AM
芽孢杆菌中钳夹-装载器-螺旋酶的相互作用 原子力显微镜揭示芽孢杆菌中DnaB-Ï "复合体的结构组织
影响因子：
5.6
作者：
Haroniti, A;Anderson, C;Soultanas, P
通讯作者：
Soultanas, P