Structure and function of a membrane component SecDF that enhances protein export.
Structure and function of a membrane component SecDF that enhances protein export.
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DOI：
10.1038/nature09980
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发表时间：
2011-05-11
期刊：
影响因子：
64.8
通讯作者：
Nureki, Osamu
中科院分区：
文献类型：
--
作者：
Tsukazaki, Tomoya;Mori, Hiroyuki;Echizen, Yuka;Ishitani, Ryuichiro;Fukai, Shuya;Tanaka, Takeshi;Perederina, Anna;Vassylyev, Dmitry G.;Kohno, Toshiyuki;Maturana, Andres D.;Ito, Koreaki;Nureki, Osamu
由SecYEG易位子和SecA ATP酶介导的蛋白质跨细菌膜的易位通过质子动力（PMF）和与SecYEG相关联的膜整合的SecDF增强。在这里，我们确定了Thermus thermophilus SecDF的晶体结构在3.3 nm分辨率，这揭示了一个假对称的，12螺旋跨膜（TM）结构域属于RND超家族和主要的周质结构域（P1和P4）。后者的更高分辨率的分析表明，P1，这被证明是结合未折叠的蛋白质，经历功能上重要的构象变化。体外分析确定了一个ATP-独立的蛋白质易位步骤，需要SecDF和PMF。电生理学分析表明，SecDF进行质子的pH值和未折叠的蛋白质依赖的方式，其中保守的天冬氨酸和精氨酸残基在TM SecD/SecF接口的质子和前蛋白的运动中发挥重要作用。因此，我们建议，SecDF功能作为膜整合的伴侣，由PMF供电，以实现ATP非依赖性蛋白质易位。
Protein translocation across the bacterial membrane, mediated by the SecYEG translocon and the SecA ATPase, is enhanced by proton-motive force (PMF) and membrane-integrated SecDF, which associates with SecYEG. Here, we determined the crystal structure of Thermus thermophilus SecDF at 3.3 Å resolution, which revealed a pseudo-symmetrical, 12-helix transmembrane (TM) domain belonging to the RND superfamily and major periplasmic domains (P1 and P4). Higher resolution analysis of the latter suggested that P1, which proved to bind an unfolded protein, undergoes functionally important conformational changes. In vitro analyses identified an ATP-independent step of protein translocation that requires both SecDF and PMF. Electrophysiological analyses revealed that SecDF conducts protons in a pH- and unfolded protein-dependent fashion, in which conserved Asp and Arg residues at the TM SecD/SecF-interface play essential roles in the movements of protons and preproteins. Therefore, we propose that SecDF functions as a membrane-integrated chaperone, powered by PMF, to achieve ATP-independent protein translocation.
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影响因子：
64.5
作者：
Economou, A;Pogliano, JA;Wickner, W
通讯作者：
Wickner, W
影响因子：
11.4
作者：
POGLIANO, JA;BECKWITH, J
通讯作者：
BECKWITH, J
DOI：
10.1073/pnas.88.6.2471
发表时间：
1991-03-01
影响因子：
11.1
作者：
DRIESSEN, AJM;WICKNER, W
通讯作者：
WICKNER, W
影响因子：
3.2
作者：
POGLIANO, KJ;BECKWITH, J
通讯作者：
BECKWITH, J
影响因子：
64.8
作者：
Tsukazaki, Tomoya;Mori, Hiroyuki;Fukai, Shuya;Ishitani, Ryuichiro;Mori, Takaharu;Dohmae, Naoshi;Perederina, Anna;Sugita, Yuji;Vassylyev, Dmitry G.;Ito, Koreaki;Nureki, Osamu
通讯作者：
Nureki, Osamu