MukE and MukF form two distinct high affinity complexes
MukE and MukF form two distinct high affinity complexes
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DOI：
10.1074/jbc.m701402200
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发表时间：
2007-05-11
影响因子：
4.8
通讯作者：
Guarne, Alba
中科院分区：
文献类型：
--
作者：
Gloyd, Melanie;Ghirlando, Rodolfo;Guarne, Alba
MukBFE复合物是大肠杆菌染色体分离和凝聚所必需的。MukB在功能上与染色体结构维持（SMC）蛋白相关。与SMC类似，MukB需要辅助蛋白（MukE和MukF）来形成用于DNA分离的功能复合物。MukF是Kleisin家族的成员，该家族包括通常介导SMC和其他辅助蛋白之间相互作用的蛋白质，这表明MukBFE和SMC复合物之间的相似性超出了MukB。虽然SMCs已被仔细研究，很少有人知道他们的附属组件的作用。在目前的工作中，我们的特点的寡聚状态的MukE和MukF使用尺寸排阻色谱和分析超离心。MukE自缔合形成二聚体（K-D 18 +/- 3 μ M），其又与MukF二聚体相互作用形成具有2：2和2：4化学计量（F：E）的两种不同的高亲和力复合物。没有发现中间复合物，因此我们提出，这两个复合物之间的平衡决定了形成的功能MukBFE与化学计量2：2：2。
The MukBFE complex is essential for chromosome segregation and condensation in Escherichia coli. MukB is functionally related to the structural maintenance of chromosomes (SMC) proteins. Similar to SMCs, MukB requires accessory proteins (MukE and MukF) to form a functional complex for DNA segregation. MukF is a member of the kleisin family, which includes proteins that commonly mediate the interaction between SMCs and other accessory proteins, suggesting that the similarities between the MukBFE and the SMC complexes extend beyond MukB. Although SMCs have been carefully studied, little is known about the roles of their accessory components. In the present work, we characterize the oligomeric states of MukE and MukF using size exclusion chromatography and analytical ultracentrifugation. MukE self-associates to form dimers (K-D 18 +/- 3 mu M), which in turn interact with the MukF dimer to form two distinct high affinity complexes having 2: 2 and 2: 4 stoichiometries (F: E). Intermediate complexes are not found, and thus we propose that the equilibrium between these two complexes determines the formation of a functional MukBFE with stoichiometry 2:2:2.