Cyanobacterial alkane biosynthesis further expands the catalytic repertoire of the ferritin-like 'di-iron-carboxylate' proteins.
Cyanobacterial alkane biosynthesis further expands the catalytic repertoire of the ferritin-like 'di-iron-carboxylate' proteins.
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DOI：
10.1016/j.cbpa.2011.02.019
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发表时间：
2011-04
影响因子：
7.8
通讯作者：
Booker, Squire J.
中科院分区：
文献类型：
--
作者：
Krebs, Carsten;Bollinger, J. Martin, Jr.;Booker, Squire J.
在类似铁蛋白的四螺旋束蛋白结构中，激活羧酸桥接非血红素二铁簇上的二氧的酶在全球碳循环（如可溶性甲烷单加氧酶）、脂肪酸生物合成（植物脂肪酰基酰基载体蛋白（ACP）去饱和酶）、DNA生物合成（Ia类核糖核苷酸还原酶（RNRs）的R2或β2亚基）和细胞铁运输（铁蛋白）等过程中起着至关重要的作用。对Ia类RNRs的经典研究很久以前就表明，这种强制性氧化二铁/氧化学反应可以用来激活酶进行还原反应，而最近对Ib类和Ic类RNRs的研究，加上对二锰过氧化氢酶的早期研究，表明该蛋白家族的成员也可以结合一个或两个Mn离子，并用它们代替铁进行氧化还原催化。这两种策略——非氧化反应的氧化活化和替代金属离子的使用——扩大了该家族的催化范围，可能包括仍待发现的活性。事实上，最近的一项研究表明，来自蓝藻细菌的脂肪醛脱碳酶（ADs），据称可以催化Cn醛氧化还原中性裂解成Cn - 1烷烃（或烯烃）和CO，也属于该酶家族，并且在结构上与其他两个具有异核（Mn-Fe）辅因子的成员最相似。在这里，我们首先简要回顾了“经典”二铁羧酸蛋白的o2依赖氧化化学的化学原理和上述两种扩大其功能范围的策略，然后考虑新发现的蓝藻ADs可能采用的金属离子和化学机制。
Enzymes that activate dioxygen at carboxylate-bridged non-heme diiron clusters residing within ferritin-like, four-helix-bundle protein architectures have crucial roles in, among other processes, the global carbon cycle (e.g., soluble methane monooxygenase), fatty acid biosynthesis [plant fatty acyl-acyl carrier protein (ACP) desaturases], DNA biosynthesis [the R2 or β2 subunits of class Ia ribonucleotide reductases (RNRs)], and cellular iron trafficking (ferritins). Classic studies on class Ia RNRs showed long ago how this obligatorily oxidative di-iron/O2 chemistry can be used to activate an enzyme for even a reduction reaction, and more recent investigations of class Ib and Ic RNRs, coupled with earlier studies on dimanganese catalases, have shown that members of this protein family can also incorporate either one or two Mn ions and use them in place of iron for redox catalysis. These two strategies – oxidative activation for non-oxidative reactions and use of alternative metal ions – expand the catalytic repertoire of the family, probably to include activities that remain to be discovered. Indeed, a recent study has suggested that fatty aldehyde decarbonylases (ADs) from cyanobacteria, purported to catalyze a redox-neutral cleavage of a Cn aldehyde to the Cn−1 alkane (or alkene) and CO, also belong to this enzyme family and are most similar in structure to two other members with heterodinuclear (Mn-Fe) cofactors. Here, we first briefly review both the chemical principles underlying the O2-dependent oxidative chemistry of the “classical” di-iron-carboxylate proteins and the two aforementioned strategies that have expanded their functional range, and then consider what metal ion(s) and what chemical mechanism(s) might be employed by the newly discovered cyanobacterial ADs.
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DOI：
10.1039/c39800000939
发表时间：
1980-01-01
影响因子：
--
作者：
DOMAZETIS, G;TARPEY, B;JAMES, BR
通讯作者：
JAMES, BR
影响因子：
4
作者：
Bollinger, J. Martin, Jr.;Diao, Yinghui;Krebs, Carsten
通讯作者：
Krebs, Carsten
DOI：
10.1073/pnas.0812971106
发表时间：
2009-04-07
影响因子：
11.1
作者：
Andersson, Charlotta S.;Hoegbom, Martin
通讯作者：
Hoegbom, Martin
影响因子：
4.7
作者：
BOURRE, JM;CASSAGNE, C;DARRIET, D
通讯作者：
DARRIET, D
影响因子：
3
作者：
Brunold, TC
通讯作者：
Brunold, TC