Mechanism of RecO recruitment to DNA by single-stranded DNA binding protein.
Mechanism of RecO recruitment to DNA by single-stranded DNA binding protein.
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DOI：
10.1093/nar/gkr199
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发表时间：
2011-08
影响因子：
14.9
通讯作者：
Korolev S
中科院分区：
文献类型：
--
作者：
Ryzhikov M;Koroleva O;Postnov D;Tran A;Korolev S
RecO是一种重组介体蛋白（RMP），对细菌中的同源重组、复制修复和DNA退火很重要。在所有途径中，单链DNA结合蛋白SSB通过保护ssDNA免于退火和重组酶结合而发挥抑制作用。相反，SSB可以通过与RecO的直接相互作用来刺激每个反应。我们提出了一个晶体结构的大肠杆菌RecO绑定到保守的SSB C-末端（SSB-Ct）。SSB-Ct以与ExoI/SSB-Ct复合物中观察到的构象相似的构象结合RecO的疏水口袋。在低和中等离子强度溶液中，疏水相互作用促进SSB-Ct与RecO和RecO/RecR复合物的结合。相反，RecO与DNA的相互作用受到盐浓度升高的抑制。缺乏SSB-Ct的SSB突变体也以盐依赖性方式抑制RecO介导的DNA退火活性。RecO和RecOR都不能使SSB与ssDNA解离。因此，在E.在大肠杆菌中，SSB通过SSB-Ct将RMP募集到ssDNA上，并且RMP可能改变SSB结合的ssDNA的构象，而无需SSB解离以启动退火或重组。有趣的是，耐辐射球菌RecO不结合SSB-Ct，并且在RecR存在下与肽弱相互作用，这表明RecO在不同生物体中介导的DNA修复途径的不同机制。
RecO is a recombination mediator protein (RMP) important for homologous recombination, replication repair and DNA annealing in bacteria. In all pathways, the single-stranded (ss) DNA binding protein, SSB, plays an inhibitory role by protecting ssDNA from annealing and recombinase binding. Conversely, SSB may stimulate each reaction through direct interaction with RecO. We present a crystal structure of Escherichia coli RecO bound to the conserved SSB C-terminus (SSB-Ct). SSB-Ct binds the hydrophobic pocket of RecO in a conformation similar to that observed in the ExoI/SSB-Ct complex. Hydrophobic interactions facilitate binding of SSB-Ct to RecO and RecO/RecR complex in both low and moderate ionic strength solutions. In contrast, RecO interaction with DNA is inhibited by an elevated salt concentration. The SSB mutant lacking SSB-Ct also inhibits RecO-mediated DNA annealing activity in a salt-dependent manner. Neither RecO nor RecOR dissociates SSB from ssDNA. Therefore, in E. coli, SSB recruits RMPs to ssDNA through SSB-Ct, and RMPs are likely to alter the conformation of SSB-bound ssDNA without SSB dissociation to initiate annealing or recombination. Intriguingly, Deinococcus radiodurans RecO does not bind SSB-Ct and weakly interacts with the peptide in the presence of RecR, suggesting the diverse mechanisms of DNA repair pathways mediated by RecO in different organisms.
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DOI：
10.1073/pnas.252633399
发表时间：
2002-11-26
影响因子：
11.1
作者：
Kantake, N;Madiraju, MVVM;Kowalczykowski, C
通讯作者：
Kowalczykowski, C
影响因子：
64.8
作者：
Cox, MM;Goodman, MF;Marians, KJ
通讯作者：
Marians, KJ
影响因子：
3.6
作者：
Kidane, D;Sanchez, H;Graumann, PL
通讯作者：
Graumann, PL
影响因子：
4.5
作者：
Bentchikou E;Servant P;Coste G;Sommer S
通讯作者：
Sommer S
影响因子：
4.8
作者：
Chow, KH;Courcelle, J
通讯作者：
Courcelle, J