Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Taiyuan 030006, China.
Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Taiyuan 030006, China; Department of Pharmacy, Shanxi Medical university, Taiyuan 030006, China.
J Inorg Biochem. 2018 Sep;186:280-293. doi: 10.1016/j.jinorgbio.2018.07.001. Epub 2018 Jul 5.
The xeroderma pigmentosum group C protein (XPC) and centrin2 are the primary initiators of global genome nucleotide excision repair (NER). Centrin, acts as a member of the EF-hand super family of calcium-binding proteins, playing roles in reconstitution of the vitro NER reaction. To understand the possible molecular and structural properties of the multiprotein process, the interactions of Euplotes octocarinatus centrin (EoCen), melittin, and DNA are described. EoCen shares a sequence identity of 66% with centrin2. Melittin possesses inverse direction hydrophobic triads-leucine-leucine-tryptophan (LLW) which are responsible for centrin binding. It is applied as a natural peptide to mimic centrin target peptide. As a result, it is proved that the integrated protein shows an endonuclease-like activity to DNA. Melittin is capable of interaction with both EoCen and DNA. More importantly, it is found that melittin displays an inhibitory effect on the endonuclease-like activity of centrin when it co-exists with EoCen and DNA in solution. Meanwhile, the DNA-melittin-EoCen ternary complex forms in the process. Quantitative analyses demonstrated by extensive biophysical assays reveal that binding of the peptide to DNA or centrin modulates the binding properties of it to another component. Furthermore, a possible positioning model of DNA and EoCen on melittin is proposed. This finding may constitute a model for that existing between centrin and its target peptide in NER process.
着色性干皮病组 C 蛋白（XPC）和中心体 2 是全基因组核苷酸切除修复（NER）的主要启动子。中心体作为钙结合蛋白 EF 手超家族的成员，在体外 NER 反应的重建中发挥作用。为了了解多蛋白过程的可能的分子和结构特性，描述了八肋游仆虫中心体（EoCen）、蜂毒素和 DNA 的相互作用。EoCen 与 centrin2 的序列同一性为 66%。蜂毒素具有反向疏水三联体-亮氨酸-亮氨酸-色氨酸（LLW），负责与中心体结合。它被用作天然肽来模拟中心体靶肽。结果表明，整合蛋白对 DNA 具有内切酶样活性。蜂毒素能够与 EoCen 和 DNA 相互作用。更重要的是，发现在溶液中 EoCen 和 DNA 共存时，蜂毒素对中心体的内切酶样活性表现出抑制作用。同时，在该过程中形成了 DNA-蜂毒素-EoCen 三元复合物。通过广泛的生物物理分析进行的定量分析表明，该肽与 DNA 或中心体的结合会调节其与另一个成分的结合特性。此外，还提出了 DNA 和 EoCen 在蜂毒素上的可能定位模型。这一发现可能构成 NER 过程中中心体与其靶肽之间存在的模型。
