Structure of T4moC, the Rieske-type ferredoxin component of toluene 4-monooxygenase
Structure of T4moC, the Rieske-type ferredoxin component of toluene 4-monooxygenase
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DOI：
10.1107/s0907444906006056
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发表时间：
2006-05-01
影响因子：
2.2
通讯作者：
Fox, BG
中科院分区：
文献类型：
--
作者：
Moe, LA;Bingman, CA;Fox, BG
以[2Fe-2S](2+)为晶态，以[2Fe-2S](2+)为中心，用单波长反常色散位相法测定了甲苯4-单加氧酶合成的Rieske型铁氧还蛋白(T4moC)的结构。该结构由10条β链组成，排列成在所有Rieske蛋白中观察到的三个反平行的β-折叠拓扑结构。T4moC的Trp69邻近[2Fe-2S]中心，与结构和功能最接近的联苯双加氧酶的Rieske型铁氧还蛋白BphF环相比，含有保守的Pro81的环与[2Fe-2S]簇的距离类似8埃。此外，与BphF中的3个氢键相比，T4moC在[2Fe-2S]团簇上有5个氢键。此外，T4moC的静电表面不同于BphF的静电表面。这些结构差异被认为可能有助于可溶性Rieske型铁氧化还原蛋白在双铁单加氧酶和顺式二氢二醇形成双加氧酶之间的进化特化。
The structure of the Rieske-type ferredoxin (T4moC) from toluene 4-monooxygenase was determined by X-ray crystallography in the [2Fe-2S](2+) state at a resolution of 1.48 angstrom using single-wavelength anomalous dispersion phasing with the [2Fe-2S] center. The structure consists of ten beta-strands arranged into the three antiparallel beta-sheet topology observed in all Rieske proteins. Trp69 of T4moC is adjacent to the [2Fe--2S] centre, which displaces a loop containing the conserved Pro81 by similar to 8 angstrom away from the [2Fe-2S] cluster compared with the Pro loop in the closest structural and functional homolog, the Rieske-type ferredoxin BphF from biphenyl dioxygenase. In addition, T4moC contains five hydrogen bonds to the [2Fe-2S] cluster compared with three hydrogen bonds in BphF. Moreover, the electrostatic surface of T4moC is distinct from that of BphF. These structural differences are identified as possible contributors to the evolutionary specialization of soluble Rieske-type ferredoxins between the diiron monooxygenases and cis-dihydrodiol-forming dioxygenases.