The copper active site of CBM33 polysaccharide oxygenases.
The copper active site of CBM33 polysaccharide oxygenases.
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DOI：
10.1021/ja402106e
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发表时间：
2013-04-24
影响因子：
15
通讯作者：
Walton, Paul H.
中科院分区：
文献类型：
--
作者：
Hemsworth, Glyn R.;Taylor, Edward J.;Kim, Robbert Q.;Gregory, Rebecca C.;Lewis, Sally J.;Turkenburg, Johan P.;Parkin, Alison;Davies, Gideon J.;Walton, Paul H.
金属依赖的真菌和细菌多糖加氧酶分别命名为GH61和CBM33，它们能够促进纤维素酶的降解，为顽固的生物质转化为生物燃料开辟了新的可能性。GH61已被证明是一种独特的金属酶，它含有一个由两个组氨酸配位的单核铜离子的活性部位，其中一个组氨酸是一种罕见的τ-N-甲基化N-末端组氨酸。我们现在报告相应的铜CBM33酶的结构和光谱特征。CBM33以高亲和力在单核部位与铜结合，显著稳定了酶。铜(II)-CBM33的X-波段EPR谱显示，铜离子与铜离子在扭曲的轴向配位球中形成了单核的2型铜位，叠氮化合物在390 nm处的UV/Vis光谱中形成了一个新的吸收带，证明了叠氮化物将配位到该配位中。该酶的三维结构中含有铜，被入射X射线光还原为铜(I)，通过对水溶液和完整的铜CBM33晶体的X射线吸收/荧光研究证实。单一的铜(I)离子以T型构型被来自两个组氨酸侧链和氨基末端的三个氮原子连接，类似于在真菌GH61中发现的内源铜配位几何结构。
The capacity of metal-dependent fungal and bacterial polysaccharide oxygenases, termed GH61 and CBM33, respectively, to potentiate the enzymatic degradation of cellulose opens new possibilities for the conversion of recalcitrant biomass to biofuels. GH61s have already been shown to be unique metalloenzymes containing an active site with a mononuclear copper ion coordinated by two histidines, one of which is an unusual τ-N-methylated N-terminal histidine. We now report the structural and spectroscopic characterization of the corresponding copper CBM33 enzymes. CBM33 binds copper with high affinity at a mononuclear site, significantly stabilizing the enzyme. X-band EPR spectroscopy of Cu(II)-CBM33 shows a mononuclear type 2 copper site with the copper ion in a distorted axial coordination sphere, into which azide will coordinate as evidenced by the concomitant formation of a new absorption band in the UV/vis spectrum at 390 nm. The enzyme’s three-dimensional structure contains copper, which has been photoreduced to Cu(I) by the incident X-rays, confirmed by X-ray absorption/fluorescence studies of both aqueous solution and intact crystals of Cu-CBM33. The single copper(I) ion is ligated in a T-shaped configuration by three nitrogen atoms from two histidine side chains and the amino terminus, similar to the endogenous copper coordination geometry found in fungal GH61.
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影响因子：
14.8
作者：
Fu, Yue;Tsui, Ho-Ching Tiffany;Bruce, Kevin E.;Sham, Lok-To;Higgins, Khadine A.;Lisher, John P.;Kazmierczak, Krystyna M.;Maroney, Michael J.;Dann, Charles E., III;Winkler, Malcolm E.;Giedroc, David P.
通讯作者：
Giedroc, David P.
影响因子：
15
作者：
KAU, LS;SPIRASOLOMON, DJ;SOLOMON, EI
通讯作者：
SOLOMON, EI
影响因子：
16.6
作者：
Himes, Richard A.;Park, Ga Young;Karlin, Kenneth D.
通讯作者：
Karlin, Kenneth D.
DOI：
10.1073/pnas.1208822109
发表时间：
2012-11-13
影响因子：
11.1
作者：
Aachmann, Finn L.;Sorlie, Morten;Vaaje-Kolstad, Gustav
通讯作者：
Vaaje-Kolstad, Gustav
影响因子：
6.3
作者：
Horn SJ;Vaaje-Kolstad G;Westereng B;Eijsink VG
通讯作者：
Eijsink VG