Crystal structures of a [NiFe] hydrogenase large subunit HyhL in an immature state in complex with a Ni chaperone HypA
Crystal structures of a [NiFe] hydrogenase large subunit HyhL in an immature state in complex with a Ni chaperone HypA
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DOI：
10.1073/pnas.1801955115
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发表时间：
2018-07-03
影响因子：
11.1
通讯作者：
Miki, Kunio
中科院分区：
文献类型：
--
作者：
Kwon, Sunghark;Watanabe, Satoshi;Miki, Kunio
Ni-Fe簇通过未知的机制被成熟蛋白如Ni伴侣HypA插入[NiFe]氢化酶的大亚基中。我们确定了一个不成熟的大亚基HyhL复合HypA从Thermococcus kodakarensis的晶体结构。结构分析表明，HyhL的N-末端区域向外延伸，并与HypA的Ni结合结构域相互作用。有趣的是，未成熟HyhL的C-末端延伸，其在成熟形式中被切割，采用与其N-末端β-链相邻的β-链。C-末端延伸的位置对应于成熟大亚基的N-末端延伸的位置，防止内肽酶进入HyhL的切割位点。这些发现表明，Ni插入到活性位点诱导空间重排的N-和C-末端尾部的HyhL，这是一个关键的检查点完成的Ni-Fe簇组装。
Ni-Fe clusters are inserted into the large subunit of [NiFe] hydrogenases by maturation proteins such as the Ni chaperone HypA via an unknown mechanism. We determined crystal structures of an immature large subunit HyhL complexed with HypA from Thermococcus kodakarensis. Structure analysis revealed that the N-terminal region of HyhL extends outwards and interacts with the Ni-binding domain of HypA. Intriguingly, the C-terminal extension of immature HyhL, which is cleaved in the mature form, adopts a beta-strand adjacent to its N-terminal beta-strands. The position of the C-terminal extension corresponds to that of the N-terminal extension of a mature large subunit, preventing the access of endopeptidases to the cleavage site of HyhL. These findings suggest that Ni insertion into the active site induces spatial rearrangement of both the N- and C-terminal tails of HyhL, which function as a key checkpoint for the completion of the Ni-Fe cluster assembly.