Structural Changes during Cysteine Desulfurase CsdA and Sulfur Acceptor CsdE Interactions Provide Insight into the trans-Persulfuration
Structural Changes during Cysteine Desulfurase CsdA and Sulfur Acceptor CsdE Interactions Provide Insight into the trans-Persulfuration
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DOI：
10.1074/jbc.m113.480277
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发表时间：
2013-09-20
影响因子：
4.8
通讯作者：
Park, SangYoun
中科院分区：
文献类型：
--
作者：
Kim, Sunmin;Park, SangYoun
在大肠杆菌中，三种半胱氨酸脱硫酶（IscS、SufS 和 CsdA）启动硫的输送，用于各种生物过程，例如 Fe-S 簇的生物发生。半胱氨酸脱硫酶的半胱氨酸残基上以过硫化物形式产生的硫在利用之前进一步转移到 Fe-S 支架（例如 IscU）或中间含半胱氨酸的硫受体（例如 TusA、SufE 和 CsdE）。在这里，我们报告了 CsdA 和 CsdA-CsdE 复合物的结构，这提供了对反式过硫化反应介导的硫转移的深入了解。结构分析表明，CsdE 中活性半胱氨酸环的构象灵活性对于接受 CsdA 半胱氨酸中的过硫化物至关重要。此外，CsdA 和 CsdE 与之前报道的半胱氨酸脱硫酶 (IscS) 和硫受体（TusA 和 IscU）的结合模式不同。此外，CsdA/SufS 和 CsdE/SufE 之间相互作用介导残基的保守性进一步表明 SufS-SufE 界面可能类似于 CsdA 和 CsdE 的界面。
In Escherichia coli, three cysteine desulfurases (IscS, SufS, and CsdA) initiate the delivery of sulfur for various biological processes such as the biogenesis of Fe-S clusters. The sulfur generated as persulfide on a cysteine residue of cysteine desulfurases is further transferred to Fe-S scaffolds (e.g. IscU) or to intermediate cysteine-containing sulfur acceptors (e.g. TusA, SufE, and CsdE) prior to its utilization. Here, we report the structures of CsdA and the CsdA-CsdE complex, which provide insight into the sulfur transfer mediated by the trans-persulfuration reaction. Analysis of the structures indicates that the conformational flexibility of the active cysteine loop in CsdE is essential for accepting the persulfide from the cysteine of CsdA. Additionally, CsdA and CsdE invoke a different binding mode than those of previously reported cysteine desulfurase (IscS) and sulfur acceptors (TusA and IscU). Moreover, the conservation of interaction-mediating residues between CsdA/SufS and CsdE/SufE further suggests that the SufS-SufE interface likely resembles that of CsdA and CsdE.