The basis of asymmetry in the SecA:SecB complex.
The basis of asymmetry in the SecA:SecB complex.
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DOI：
10.1016/j.jmb.2014.12.008
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发表时间：
2015-02-27
影响因子：
5.6
通讯作者：
Randall, Linda L.
中科院分区：
文献类型：
--
作者：
Suo, Yuying;Hardy, Simon J. S.;Randall, Linda L.
在大肠杆菌中的输出期间，SecB（在结构上组织为二聚体的二聚体的同源四聚体）与SecA的两个原聚体形成复合物，SecA是提供能量以经由SecYEG易位子通过膜转移前体多肽的ATP酶。SecB上有两个接触区域稳定SecA：SecB复合物：一个是SecB四聚体的平坦侧，第二个是SecB的C末端13个残基。这些联系人在复杂的分布是不对称的。破坏SecA和SecB侧面之间的接触导致仅释放SecA的一个原聚体，产生化学计量SecA 1：SecB 4的复合物。该复合体介导输出;然而，ATP水解与前体通过易位子的运动的偶联比SecA 2：SecB 4复合物的偶联效率低得多。在这里，我们使用异源四聚体物种的SecB了解的来源的不对称性的联系及其作用的复杂的功能。提出的相互作用模型表明SecA和SecB之间的结合可能会降低前体多肽对SecB的亲和力并促进向SecA的转移。
During export in Escherichia coli, SecB, a homotetramer, structurally organized as a dimer of dimers, forms a complex with two protomers of SecA, which is the ATPase that provides energy to transfer a precursor polypeptide through the membrane via the SecYEG translocon. There are two areas of contact on SecB that stabilize the SecA:SecB complex: one, the flat sides of the SecB tetramer and the second, the C-terminal thirteen residues of SecB. These contacts within the complex are distributed asymmetrically. Breaking contact between SecA and the sides of SecB results in release of only one protomer of SecA yielding a complex of stoichiometry SecA1:SecB4. This complex mediates export; however, the coupling of ATP hydrolysis to movements of the precursor through the translocon is much less efficient than the coupling by the SecA2:SecB4 complex. Here we used heterotetrameric species of SecB to understand the source of the asymmetry in the contacts and its role in the functioning of the complex. The model of interactions presented suggests a way that binding between SecA and SecB might decrease the affinity of precursor polypeptides for SecB and facilitate the transfer to SecA.
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影响因子：
5.6
作者：
Crane, Jennine M.;Suo, Yuying;Randall, Linda L.
通讯作者：
Randall, Linda L.
影响因子：
8
作者：
Randall, LL;Topping, TB;Hardy, SJS
通讯作者：
Hardy, SJS
影响因子：
3.2
作者：
Mao, Chunfeng;Hardy, Simon J. S.;Randall, Linda L.
通讯作者：
Randall, Linda L.
影响因子：
2.9
作者：
VANHOLDE, KE;WEISCHET, WO
通讯作者：
WEISCHET, WO
影响因子：
8
作者：
Randall, LL;Crane, JM;Hardy, SJS
通讯作者：
Hardy, SJS