Structure of a [NiFe] Hydrogenase Maturation Protease HycI Provides Insights into Its Substrate Selectivity
Structure of a [NiFe] Hydrogenase Maturation Protease HycI Provides Insights into Its Substrate Selectivity
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[NiFe] 氢化酶成熟蛋白酶 HycI 的结构提供了对其底物选择性的见解
DOI：
10.1016/j.bbrc.2018.03.058
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
and K. Miki
中科院分区：
文献类型：
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作者：
S. Kwon;Y. Nishitani;Y;Hirao;T. Kanai;H. Atomi;and K. Miki
[NiFe]氢化酶的未成熟大亚基在与其他亚基组装之前在翻译后过程的最后步骤中通过特异性蛋白酶进行C-末端切割。据报道，来自于Thermococcus kodakarensis的[NiFe]氢化酶成熟蛋白酶HycI（TkHycI）具有靶向来自于Thermococcus kodakarensis的膜结合氢化酶大亚基MbhL的催化能力。然而，其底物识别的详细机制仍然难以捉摸。我们在1.59 nm分辨率下测定了TkHycI的晶体结构，以阐明TkHycI如何识别其自身的底物MbhL。虽然TkHycI的整体结构与其同源蛋白酶TkHybD相似，但TkHycI采用比TkHybD更大的环，从而产生宽而深的裂缝。我们分析了可能参与其底物识别的TkHycI裂缝的结构特性。我们的研究结果为TkHycI的底物选择性提供了新颖而深刻的见解。
The immature large subunit of [NiFe] hydrogenases undergoes C-terminal cleavage by a specific protease in the final step of the post-translational process before assembly with other subunits. It has been reported that the [NiFe] hydrogenase maturation protease HycI fromThermococcus kodakarensis(TkHycI) has the catalytic ability to target the membrane-bound hydrogenase large subunit MbhL fromT. kodakarensis. However, the detailed mechanism of its substrate recognition remains elusive. We determined the crystal structure of TkHycI at 1.59 Å resolution to clarify how TkHycI recognizes its own substrate MbhL. Although the overall structure of TkHycI is similar to that of its homologous protease TkHybD, TkHycI adopts a larger loop than TkHybD, thereby creating a broad and deep cleft. We analyzed the structural properties of the TkHycI cleft probably involved in its substrate recognition. Our findings provide novel and profound insights into the substrate selectivity of TkHycI.