Protein surface charge effect on 3D domain swapping in cells for c-type cytochromes
Protein surface charge effect on 3D domain swapping in cells for c-type cytochromes
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蛋白质表面电荷对细胞中 c 型细胞色素 3D 结构域交换的影响
DOI：
10.1016/j.bbapap.2019.140265
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Hirota Shun
中科院分区：
文献类型：
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作者：
Yang Hongxu;Yamanaka Masaru;Nagao Satoshi;Yasuhara Kazuma;Shibata Naoki;Higuchi Yoshiki;Hirota Shun
多型细胞色素（cytochrome，cyts）可以形成结构域交换的寡聚体。带正电荷的嗜热氢菌（HT）细胞色素（cyt）c552在大肠杆菌（Escherichia coli，E. coli）表达系统中表达时会形成结构域交换的寡聚体，但影响寡聚化的因素尚未揭示。在这里，我们发现，带负电荷的希瓦氏菌cytc 552和铜绿假单胞菌cytc 551的结构域交换二聚体的结构，其中的N-末端螺旋之间的原聚体，类似的结构域交换的结构。在大肠杆菌中，带正电荷的马cytc和HT cytc 552结构域在表达过程中发生交换，而带负电荷的PA cytc 551和SV cytc 55则没有发生交换。HT cytc 552在大肠杆菌中的表达过程中形成了寡聚体，HT cytc 552与翻译后信号肽结合，通过细胞质膜转运，而PA cytc 551则不与任何一个信号肽结合。HT cytc 552在大肠杆菌中在存在和不存在稀有密码子的情况下形成寡聚体。通过在折叠过程中添加带负电荷的脂质体，马cytc和HT cytc 552的体外折叠获得了更多的寡聚体，而PA cytc 551和SV cytc 5的体外折叠的寡聚体数量并未因添加而发生显着变化。这些结果表明，蛋白质的表面电荷影响细胞中c型细胞的寡聚化;带正电荷的c型细胞在带负电荷的膜上组装，诱导折叠过程中形成结构域交换的寡聚体。
Manyc-type cytochromes (cyts) can form domain-swapped oligomers. The positively chargedHydrogenobacter thermophilus(HT) cytochrome (cyt)c552forms domain-swapped oligomers during expression in theEscherichia coli(E. coli) expression system, but the factors influencing the oligomerization remain unrevealed. Here, we found that the dimer of the negatively charged Shewanellaviolacea(SV) cytc5exhibits a domain-swapped structure, in which the N-terminal helix is exchanged between protomers, similar to the structures of the HT cytc552and Pseudomonas aeruginosa (PA) cytc551domain-swapped dimers. Positively charged horse cytcand HT cytc552domain swapped during expression inE. coli, whereas negatively charged PA cytc551and SV cytc5did not. Oligomers were formed during expression inE. colifor HT cytc552attached to either a co- or post-translational signal peptide for transportation through the cytoplasm membrane, but not for PA cytc551attached to either signal peptide. HT cytc552formed oligomers inE. coliin the presence and absence of rare codons. More oligomers were obtained from thein vitrofolding of horse cytcand HT cytc552by the addition of negatively charged liposomes during folding, whereas the amount of oligomers for thein vitrofolding of PA cytc551and SV cytc5did not change significantly by the addition. These results indicate that the protein surface charge affects the oligomerization ofc-type cyts in cells; positively chargedc-type cyts assemble on a negatively charged membrane, inducing formation of domain-swapped oligomers during folding.