Geometric and electrostatic study of the [4Fe-4S] cluster of adenosine-5'-phosphosulfate reductase from broken symmetry density functional calculations and extended X-ray absorption fine structure spectroscopy.
Geometric and electrostatic study of the [4Fe-4S] cluster of adenosine-5'-phosphosulfate reductase from broken symmetry density functional calculations and extended X-ray absorption fine structure spectroscopy.
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DOI：
10.1021/ic200446c
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发表时间：
2011-07-18
影响因子：
4.6
通讯作者：
Noodleman L
中科院分区：
文献类型：
--
作者：
Bhave DP;Han WG;Pazicni S;Penner-Hahn JE;Carroll KS;Noodleman L
Adenosine-5’-phosphosulfate reductase (APSR) is an iron-sulfur protein that catalyses the reduction of adenosine-5’-phosphosulfate (APS) to sulfite. APSR coordinates to a [4Fe-4S] cluster via a conserved CC-X~80-CXXC motif and the cluster is essential for catalysis. Despite extensive functional, structural and spectroscopic studies, the exact role of the iron-sulfur cluster in APS reduction remains unknown. To gain an understanding into the role of the cluster, density functional theory (DFT) analysis and extended X-ray fine structure spectroscopy (EXAFS) have been performed to reveal insights into the coordination, geometry and electrostatics of the [4Fe-4S] cluster. XANES data confirms that the cluster is in the [4Fe-4S]2+ state in both native and substrate-bound APSR while EXAFS data recorded at ~0.1 Å resolution indicates that there is no significant change in the structure of the [4Fe-4S] cluster between the native and substrate-bound forms of the protein. On the other hand, DFT calculations provide an insight into the subtle differences between the geometry of the cluster in the native and APS-bound forms of APSR. A comparison between models with and without the tandem cysteine pair coordination of the cluster suggests a role for the unique coordination in facilitating a compact geometric structure and ‘fine-tuning’ the electronic structure to prevent reduction of the cluster. Further, calculations using models in which residue Lys144 is mutated to Ala confirm the finding that Lys144 serves as a crucial link in the interactions involving the [4Fe-4S] cluster and APS.
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DOI：
10.1073/pnas.0337638100
发表时间：
2003-02-04
影响因子：
11.1
作者：
Chapman, E;Bryan, MC;Wong, CH
通讯作者：
Wong, CH
影响因子：
2.8
作者：
Han, Wen-Ge;Noodleman, Louis
通讯作者：
Noodleman, Louis
影响因子：
5.6
作者：
Chartron, Justin;Carroll, Kate S.;Stout, C. David
通讯作者：
Stout, C. David
影响因子：
2.9
作者：
BASHFORD, D;KARPLUS, M
通讯作者：
KARPLUS, M
影响因子：
2.9
作者：
Antosiewicz, J;McCammon, JA;Gilson, MK
通讯作者：
Gilson, MK