C-terminal aromatic residue of Plasmodium ferredoxin important for the interaction with ferredoxin: NADP(H) oxidoreductase: possible involvement for artemisinin resistance of human malaria parasites
C-terminal aromatic residue of Plasmodium ferredoxin important for the interaction with ferredoxin: NADP(H) oxidoreductase: possible involvement for artemisinin resistance of human malaria parasites
复制标题
DOI：
10.1093/jb/mvaa060
复制
发表时间：
2020-10-01
影响因子：
2.7
通讯作者：
Hase, Toshiharu
中科院分区：
文献类型：
--
作者：
Kimata-Ariga, Yoko;Sakamoto, Asako;Hase, Toshiharu
疟疾寄生虫(疟原虫sp.)含有一种由叶绿体衍生的细胞器，称为顶生质体，对寄生虫的生长是必不可少的。在这个细胞器中，由植物型铁还蛋白(FD)和FD：NADP(H)氧化还原酶(FNR)组成的氧化还原系统为关键的代谢途径提供还原动力。恶性疟原虫Fd(PFFD)和FNR(PfFNR)之间的电子传递比植物Fd和FNR具有更高的亲和力和特异性。我们通过聚焦于PFFD的质膜特定区域来研究这种优越的蛋白质-蛋白质相互作用的结构基础。通过在植物FD和PFFD之间交换C-末端的三个残基，揭示了PFFD的C-末端区域对与PfFNR的电子转移的显著贡献。进一步对PfFdC末端残基的定点突变表明，第96和97位芳香族残基的存在有助于PfFNR的低K-m。使用荧光和量热测量进行的物理结合分析支持这一结果。最近有报道称，Pffd基因第97位Asp突变为Tyr与恶性疟原虫对一线抗疟疾药物青蒿素的耐药性密切相关。因此，PfFd97Y蛋白与PfFNR的相互作用增强可能参与了人疟原虫对青蒿素的耐药性。
The malaria parasite (Plasmodium sp.) contains a plastid-derived organelle called the apicoplast, which is essential for the growth of the parasite. In this organelle, a redox system comprising plant-type ferredoxin (Fd) and Fd: NADP(H) oxidoreductase (FNR) supplies reducing power for the crucial metabolic pathways. Electron transfer between Plasmodium falciparum Fd (PfFd) and FNR (PfFNR) is performed with higher affinity and specificity than those of plant Fd and FNR. We investigated the structural basis for such superior protein-protein interaction by focussing on the Plasumodium-specific regions of PfFd. Significant contribution of the C-terminal region of PfFd for the electron transfer with PfFNR was revealed by exchanging the C-terminal three residues between plant Fd and PfFd. Further site-directed mutagenesis of the PfFd C-terminal residues indicated that the presence of aromatic residue at Positions 96 and 97 contributes to the lower K-m for PfFNR. Physical binding analyses using fluorescence and calorimetric measurements supported the results. A mutation from Asp to Tyr at position 97 of PfFd was recently reported to be strongly associated with P. falciparum resistance to artemisinin, the front line anti-malarial drug. Thus, the enhanced interaction of PfFd D97Y protein with PfFNR could be involved in artemisinin resistance of human malaria parasites.