Structure and function of CYP108D1 from Novosphingobium aromaticivorans DSM12444: an aromatic hydrocarbon-binding P450 enzyme
Structure and function of CYP108D1 from Novosphingobium aromaticivorans DSM12444: an aromatic hydrocarbon-binding P450 enzyme
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DOI：
10.1107/s090744491200145x
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发表时间：
2012-03-01
影响因子：
2.2
通讯作者：
Wong, Luet-Lok
中科院分区：
文献类型：
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作者：
Bell, Stephen G.;Yang, Wen;Wong, Luet-Lok
来自Novosphingobiumaromaticivorans DSM12444的CYP108D1结合一系列芳烃，如菲，联苯和苯基环己烷。它的结构与CYP108A1 （P450terp）密切相关，CYP108A1 （P450terp）是一种α -萜烯醇氧化酶。这两种酶的活性位点组成和结构非常相似；最显著的变化是CYP108A1中的Glu77和Thr103被CYP108D1中的Thr79和Val105所取代。其他残基差异导致CYP108D1中更大、更疏水的通路。这些结构特征可能解释了CYP108D1与α -松油醇结合较弱的原因，并且当与活性位点存在的三个疏水苯丙氨酸残基结合时，促进了芳烃的结合。CYP108D1的血-近端表面显示出与CYP101D1、CYP101A1和CYP108A1不同的电荷分布和拓扑结构，包括CYP108D1近端环上明显的扭结，这可能导致与这三种P450酶的氧化还原伙伴[2Fe-2S]铁氧还蛋白Arx、putidaredoxin和terpredoxin互补性差。苯基环己烷结合的CYP108D1 （-401 mV）意想不到的低还原电位也可能是这些铁氧化还原蛋白活性低的原因。CYP108D1似乎是一种芳香烃羟化酶，需要不同的电子转移辅助因子蛋白。
CYP108D1 from Novosphingobiumaromaticivorans DSM12444 binds a range of aromatic hydrocarbons such as phenanthrene, biphenyl and phenylcyclohexane. Its structure, which is reported here at 2.2 angstrom resolution, is closely related to that of CYP108A1 (P450terp), an alpha-terpineol-oxidizing enzyme. The compositions and structures of the active sites of these two enzymes are very similar; the most significant changes are the replacement of Glu77 and Thr103 in CYP108A1 by Thr79 and Val105 in CYP108D1. Other residue differences lead to a larger and more hydrophobic access channel in CYP108D1. These structural features are likely to account for the weaker alpha-terpineol binding by CYP108D1 and, when combined with the presence of three hydrophobic phenylalanine residues in the active site, promote the binding of aromatic hydrocarbons. The haem-proximal surface of CYP108D1 shows a different charge distribution and topology to those of CYP101D1, CYP101A1 and CYP108A1, including a pronounced kink in the proximal loop of CYP108D1, which may result in poor complementarity with the [2Fe-2S] ferredoxins Arx, putidaredoxin and terpredoxin that are the respective redox partners of these three P450 enzymes. The unexpectedly low reduction potential of phenylcyclohexane-bound CYP108D1 (-401 mV) may also contribute to the low activity observed with these ferredoxins. CYP108D1 appears to function as an aromatic hydrocarbon hydroxylase that requires a different electrontransfer cofactor protein.