ATP binding to the motor domain from an ABC transporter drives formation of a nucleotide sandwich dimer
ATP binding to the motor domain from an ABC transporter drives formation of a nucleotide sandwich dimer
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DOI：
10.1016/s1097-2765(02)00576-2
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发表时间：
2002-07-01
期刊：
影响因子：
16
通讯作者：
Hunt, JF
中科院分区：
文献类型：
--
作者：
Smith, PC;Karpowich, N;Hunt, JF
有人提出，ATP结合盒（ABC）转运蛋白的反应循环是由其ABC马达结构域在相互界面结合ATP后的二聚化驱动的。然而，对于来自ABC转运蛋白的ABC，没有观察到这样的ATP夹心复合物。在本文中，我们报告了一个稳定的climer形成的MJ0796 ABC，这是水解失活，由于突变的催化碱的E171 Q突变体的晶体结构。结构显示对称二聚体，其中两个ATP分子各自夹在一个亚基中的步行者A基序和另一个亚基中的LSGGQ特征基序之间。这些结果建立了ABC转运泵的动力冲程的立体化学基础。
It has been proposed that the reaction cycle of ATP binding cassette (ABC) transporters is driven by dimerization of their ABC motor domains upon binding ATP at their mutual interface. However, no such ATP sandwich complex has been observed for an ABC from an ABC transporter. In this paper, we report the crystal structure of a stable climer formed by the El 71 Q mutant of the MJ0796 ABC, which is hydrolytically inactive due to mutation of the catalytic base. The structure shows a symmetrical dimer in which two ATP molecules are each sandwiched between the Walker A motif in one subunit and the LSGGQ signature motif in the other subunit. These results establish the stereochemical basis of the power stroke of ABC transporter pumps.