Asymmetric dimeric structure of ferredoxin-NAD(P)+ oxidoreductase from the green sulfur bacterium Chlorobaculum tepidum: implications for binding ferredoxin and NADP+.
Asymmetric dimeric structure of ferredoxin-NAD(P)+ oxidoreductase from the green sulfur bacterium Chlorobaculum tepidum: implications for binding ferredoxin and NADP+.
复制标题
来自绿硫细菌温热绿杆菌的铁氧还蛋白-NAD(P)氧化还原酶的不对称二聚体结构：对铁氧还蛋白和NADP结合的影响。
DOI：
10.1016/j.jmb.2010.06.024
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发表时间：
2010
影响因子：
5.6
通讯作者：
G. Kurisu
中科院分区：
文献类型：
--
作者：
N. Muraki;D. Seo;T. Shiba;T. Sakurai;G. Kurisu
铁氧化还蛋白-NAD(P)+氧化还原酶（FNR）在光合作用电子传递链的最后一步用还原的铁氧化还蛋白（Fd）催化NAD(P)+还原为NAD(P)H。来自绿硫杆菌的FNR在功能上类似于植物型FNR，但在结构上与nadph依赖性硫氧还蛋白还原酶（TrxR）具有同源性。本文以2.4 Å分辨率报道了C. tepidum FNR的晶体结构，揭示了一种独特的结构-功能关系。温草FNR由两个结合FAD和NAD(P)H的功能结构域组成，其结构域不对称排列。一个NAD(P)H结构域以开放形式存在，另一个与等效的NAD(P)H结构域以相对封闭形式存在。为了研究柔性铰链的重要性，我们对连接这两个结构域的铰链区域进行了定点突变。NAD(P)H结构域的不对称性以及与TrxR的比较表明，铰链运动可能参与了吡啶核苷酸结合和Fd的结合。令人惊讶的是，晶体结构揭示了一个额外的c端亚结构域，该结构域通过Phe337的π-π堆叠和FAD的异alloxazine环与一个原聚体相互作用。这个堆叠的Phe337的位置与植物型FNR的保守的c端Tyr残基和TrxR的活性位点二硫醇几乎相同，这意味着C. tepidum FNR的酶促反应具有独特的结构基础。
Ferredoxin-NAD(P)+oxidoreductase (FNR) catalyzes the reduction of NAD(P)+to NAD(P)H with the reduced ferredoxin (Fd) during the final step of the photosynthetic electron transport chain. FNR from the green sulfur bacterium Chlorobaculum tepidum is functionally analogous to plant-type FNR but shares a structural homology to NADPH-dependent thioredoxin reductase (TrxR). Here, we report the crystal structure of C. tepidum FNR to 2.4 Å resolution, which reveals a unique structure–function relationship. C. tepidum FNR consists of two functional domains for binding FAD and NAD(P)H that form a homodimer in which the domains are arranged asymmetrically. One NAD(P)H domain is present as the open form, the other with the equivalent NAD(P)H domain as the relatively closed form. We used site-directed mutagenesis on the hinge region connecting the two domains in order to investigate the importance of the flexible hinge. The asymmetry of the NAD(P)H domain and the comparison with TrxR suggested that the hinge motion might be involved in pyridine nucleotide binding and binding of Fd. Surprisingly, the crystal structure revealed an additional C-terminal sub-domain that tethers one protomer and interacts with the other protomer by π-π stacking of Phe337 and the isoalloxazine ring of FAD. The position of this stacking Phe337 is almost identical with both of the conserved C-terminal Tyr residues of plant-type FNR and the active site dithiol of TrxR, implying a unique structural basis for enzymatic reaction of C. tepidum FNR.
DOI：
10.1046/j.1432-1327.2000.01702.x
发表时间：
2000-10
期刊：
European journal of biochemistry
影响因子：
--
作者：
C. Williams;L. Arscott;S. Müller;B. Lennon;M. Ludwig;Pan‐Fen Wang;D. M. Veine;K. Becker;R. Schirmer
通讯作者：
C. Williams;L. Arscott;S. Müller;B. Lennon;M. Ludwig;Pan‐Fen Wang;D. M. Veine;K. Becker;R. Schirmer
影响因子：
5.6
作者：
Berkholz, Donald S.;Faber, H. Richard;Savvides, Savvas N.;Karplus, P. Andrew
通讯作者：
Karplus, P. Andrew
影响因子：
56.9
作者：
Lennon, BW;Williams, CH;Ludwig, ML
通讯作者：
Ludwig, ML