Conformation of a plasmid replication initiator protein affects its proteolysis by ClpXP system.
Conformation of a plasmid replication initiator protein affects its proteolysis by ClpXP system.
复制标题
质粒复制起始蛋白的构象影响 ClpXP 系统的蛋白水解作用。
DOI：
10.1002/pro.68
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Konieczny,Igor
中科院分区：
文献类型：
--
作者：
Pierechod,Marcin;Nowak,Agnieszka;Saari,Anna;Purta,Elzbieta;Bujnicki,JanuszM;Konieczny,Igor
来自DNA复制启动子Rep家族的蛋白质主要以二聚体形式存在，但只有单体可以通过与复制起点（ori）相互作用来启动DNA复制。在这项研究中，我们研究了宽宿主范围质粒RK2复制起始蛋白TrfA的激活（单体化）和降解，我们发现它是一类含有翼螺旋（WH）结构域的DNA复制起始物的成员。我们的体内和体外实验表明，ClpX依赖性激活TrfA，导致复制活性蛋白单体和影响TrfA二聚体形成的突变，导致ClpXP蛋白水解系统抑制TrfA蛋白降解。这些数据显示，TrfA单体和二聚体以显著不同的速率降解。我们的数据还表明，质粒复制启动子的活性和稳定性在E。只有当蛋白质维持二聚体形式时，大肠细胞才会受到ClpXP系统的影响。
Proteins from the Rep family of DNA replication initiators exist mainly as dimers, but only monomers can initiate DNA replication by interaction with the replication origin (ori). In this study, we investigated both the activation (monomerization) and the degradation of the broad‐host‐range plasmid RK2 replication initiation protein TrfA, which we found to be a member of a class of DNA replication initiators containing winged helix (WH) domains. Ourin vivoandin vitroexperiments demonstrated that the ClpX‐dependent activation of TrfA leading to replicationally active protein monomers and mutations affecting TrfA dimer formation, result in the inhibition of TrfA protein degradation by the ClpXP proteolytic system. These data revealed that the TrfA monomers and dimers are degraded at substantially different rates. Our data also show that the plasmid replication initiator activity and stability inE. colicells are affected by ClpXP system only when the protein sustains dimeric form.