Kowalska Ewa, Strzałka Wojciech, Oyama Takuji
Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland.
Faculty of Life and Environmental Sciences, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi 400-8510, Japan.
Acta Biochim Pol. 2020 Mar 19;67(1):49-52. doi: 10.18388/abp.2020_2896.
DNA replication is an important event for all living organisms and the mechanism is essentially conserved from archaea, bacteria to eukaryotes. Proliferating cell nuclear antigen (PCNA) acts as the universal platform for many DNA transacting proteins. Flap endonuclease 1 (FEN1) is one such enzyme whose activity is largely affected by the interaction with PCNA. To elucidate the key interactions between plant PCNA and FEN1 and possible structural change of PCNA caused by binding of FEN1 at the atomic level, crystallization and preliminary studies of X-ray diffraction of crystals of Arabidopsis thaliana PCNA2 (AtPCNA2) alone and in a complex with a peptide derived from AtFEN1, which contains a typical PCNA-interacting protein (PIP)-box motif, were performed. Both peptide-free and peptide-bound AtPCNA2s were crystallized using the same reservoir solution but in different crystal systems, indicating that the peptide affected the intermolecular interactions in the crystals. Crystals of AtPCNA2 belonged to the hexagonal space group P63, while those of the peptide-bound AtPCNA2 belonged to the rhombohedral space group H3, both of which could contain the functional homo-trimers.
DNA复制对所有生物来说都是一个重要事件，其机制在古细菌、细菌到真核生物中基本保守。增殖细胞核抗原（PCNA）是许多DNA相互作用蛋白的通用平台。瓣状核酸内切酶1（FEN1）就是这样一种酶，其活性在很大程度上受与PCNA相互作用的影响。为了在原子水平上阐明植物PCNA与FEN1之间的关键相互作用以及FEN1结合导致的PCNA可能的结构变化，我们对拟南芥PCNA2（AtPCNA2）单独以及与来自AtFEN1的含有典型PCNA相互作用蛋白（PIP）框基序的肽形成的复合物进行了结晶和X射线衍射初步研究。不含肽和结合肽的AtPCNA2均使用相同的储液进行结晶，但属于不同的晶体系统，这表明该肽影响了晶体中的分子间相互作用。AtPCNA2的晶体属于六方空间群P63，而结合肽的AtPCNA2的晶体属于菱面体空间群H3，两者都可能包含功能性同源三聚体。
