Solution structure of monomeric human FAM96A
Solution structure of monomeric human FAM96A
复制标题
单体人FAM96A的溶液结构
DOI：
10.1007/s10858-013-9746-6
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发表时间：
2013-08-01
影响因子：
2.7
通讯作者：
Xia, Bin
中科院分区：
文献类型：
--
作者：
Ouyang, Bingjie;Wang, Lei;Xia, Bin
未知功能域59（DUF 59）是存在于细菌、古细菌和一些真核生物中的蛋白质家族，在进化过程中高度保守。据报道，来自原核生物的该家族成员参与生理功能，如苯乙酸代谢（Ferrandez et al. 1998; Olivera et al. 1998）和金属硫簇合成（Lezhneva et al. 2004; Luo et al. 2012; Schwenkert et al. 2010）。已经确定了细菌DUF 59的三种结构（Almeida等人，2005），并且它们都是单体形式。在哺乳动物中只有两种DUF 59蛋白，FAM 96 A和FAM 96 B（具有序列相似性的家族96个成员A和B）。FAM 96 A含有160个氨基酸残基，N端27个氨基酸残基预测为信号肽，28-160个氨基酸残基与DUF 59家族的氨基酸残基高度同源。先前的研究表明，FAM 96 A mRNA在巨噬细胞中富集，表明FAM 96 A作为炎症调节剂和抗炎设计靶点的潜在重要性（Chen et al. 2012）。还发现FAM 96 A在体外和体内与Ciao 1相互作用（Chen et al.2012），Ciao 1作为细胞质FeS组装（CIA）蛋白发挥作用（Srinivasan et al.2007），并调节WT 1（Wilms肿瘤抑制蛋白）在细胞生长和分化中的生理功能（Johnstone et al.1998）。最近报道，当在大肠杆菌中表达时，存在FAM 96 A的单体、二聚体和寡聚体形式（Chen等人，2012; Mas等人，2012）。二聚体FAM 96 A的晶体结构是结构域交换的形式，但柔性环（残基：T122-E127）区域缺乏相关的电子密度导致不确定的结构域交换模式。有趣的是，单体FAM 96 A在结晶过程中转化为独特的结构域交换二聚体。因此，单体FAM 96 A的封闭构象结构尚未得到。在这项工作中，我们确定的单体FAM 96 A的溶液结构，使用NMR光谱，这提供了结构的洞察形成domainswapped二聚体。此外，我们研究了温度依赖性的单体和二聚体FAM 96 A之间的相互转化，以及低聚物的形成。
Domain of unknown function 59 (DUF59) is a protein family found in bacteria, archaea and some eukaryotes, which is highly conserved during evolution. Members of this family from prokaryotes are reported to be involved in physiological functions such as metabolism of phenylacetic acid (Ferrandez et al. 1998; Olivera et al. 1998) and metalsulfur cluster synthesis (Lezhneva et al. 2004; Luo et al. 2012; Schwenkert et al. 2010). Three structures of bacterial DUF59s have been determined (Almeida et al. 2005) and all of them are in monomeric form. There are only two DUF59 proteins in mammals, FAM96A and FAM96B (family with sequence similarity 96 member A and B). FAM96A contains 160 amino acid residues, and its N-terminal 27 residues are predicted to be a signal peptide and residues 28–160 are highly homologous to those of DUF59 family. Previous study reveals that FAM96A mRNA is enriched in macrophages, indicating the potential importance of FAM96A as regulator of inflammation and target for anti-inflammatory design (Chen et al. 2012). FAM96A was also found to interact both in vitro and in vivo with Ciao 1 (Chen et al. 2012), which functions as a cytoplasmic FeS assembly (CIA) protein (Srinivasan et al. 2007) and regulates the physiological function of WT1 (Wilms tumor suppressor protein) in cell growth and differentiation (Johnstone et al. 1998). It was reported recently that there are monomeric, dimeric and oligomeric forms of FAM96A when expressed in Escherichia coli (Chen et al. 2012; Mas et al. 2012). Crystal structure of dimeric FAM96A is a domain-swapped form, but the lack of associated electron density for flexible loop (residues: T122–E127) region leads to uncertain domain swapping mode. Intriguingly, the monomeric FAM96A was converted into a distinct domain-swapped dimer during crystallization. Therefore, the closed conformational structure of the monomeric FAM96A has not been obtained.In this work, we determine the solution structure of the monomeric FAM96A using NMR spectroscopy, which provides structural insight for the formation of domainswapped dimer. In addition, we investigate the temperature-dependent interconversion between the monomeric and dimeric FAM96A, and the formation of oligomer.