Redox regulation of CF1-ATPase involves interplay between the gamma-subunit neck region and the turn region of the betaDELSEED-loop
Redox regulation of CF1-ATPase involves interplay between the gamma-subunit neck region and the turn region of the betaDELSEED-loop
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CF1-ATPase 的氧化还原调节涉及 γ 亚基颈部区域和 betaDELSEED 环转角区域之间的相互作用
DOI：
10.1016/j.bbabio.2015.01.013
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Toru Hisabori
中科院分区：
文献类型：
--
作者：
Felix Buchert;Hiroki Konno;Toru Hisabori
ATP合酶的可溶性F1复合物（FoF 1）能够水解ATP，由最小催化核心亚基α3β3γ完成。蓝藻F1和叶绿体F1（CF 1）的一个特殊特征是在γ-亚基中插入一个氨基酸序列。插入稍微延伸到含有两个额外的半胱氨酸的CF 1酶中，用于通过巯基调节来调节ATP酶活性。通过将菠菜CF 1的含半胱氨酸片段插入到蓝藻γ亚基中，将该分子开关转移到嵌合F1中[Y. Kim等人，氧化还原调节含有硫醇调节开关的蓝藻F1-ATP酶的旋转，J Biol Chem，286（2011）9071-9078]。在氧化条件下，获得的F1往往陷入ADP抑制状态，一种常见的调节机制，以防止浪费ATP水解不利的情况下。然而，γ-亚基上的巯基调节位点和β-亚基上的催化位点之间的信息流仍然不清楚。在这里，我们阐明了β DELSEED环和γ亚基颈区结构元件之间CF 1-ATP酶氧化还原调节的可能相互作用，即，α-螺旋γ-末端的最凸部分。在β亚基上分配关键残基，其接收由γ亚基上的二硫键/二硫醇形成产生的构象变化信号。突变体对ATP酶氧化还原调节的反应范围从丢失到过敏。此外，突变交联实验和氧化还原调节的反转表明，γ-氧化还原状态可能通过βDELSEED基序区域的重定向来调节亚基界面。
The soluble F1complex of ATP synthase (FoF1) is capable of ATP hydrolysis, accomplished by the minimum catalytic core subunits α3β3γ. A special feature of cyanobacterial F1and chloroplast F1(CF1) is an amino acid sequence inserted in the γ-subunit. The insertion is extended slightly into the CF1enzyme containing two additional cysteines for regulation of ATPase activity via thiol modulation. This molecular switch was transferred to a chimeric F1by inserting the cysteine-containing fragment from spinach CF1into a cyanobacterial γ-subunit [Y. Kim et al., redox regulation of rotation of the cyanobacterial F1-ATPase containing thiol regulation switch, J Biol Chem, 286 (2011) 9071–9078]. Under oxidizing conditions, the obtained F1tends to lapse into an ADP-inhibited state, a common regulation mechanism to prevent wasteful ATP hydrolysis under unfavorable circumstances. However, the information flow between thiol modulation sites on the γ-subunit and catalytic sites on the β-subunits remains unclear. Here, we clarified a possible interplay for the CF1-ATPase redox regulation between structural elements of the βDELSEED-loop and the γ-subunit neck region, i.e., the most convex part of the α-helical γ-termini. Critical residues were assigned on the β-subunit, which received the conformation change signal produced by disulfide/dithiol formation on the γ-subunit. Mutant response to the ATPase redox regulation ranged from lost to hypersensitive. Furthermore, mutant cross-link experiments and inversion of redox regulation indicated that the γ-redox state might modulate the subunit interface via reorientation of the βDELSEED motif region.