Chlamydial ribonucleotide reductase: tyrosyl radical function in catalysis replaced by the FeIII-FeIV cluster.
Chlamydial ribonucleotide reductase: tyrosyl radical function in catalysis replaced by the FeIII-FeIV cluster.
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衣原体核糖核苷酸还原酶：催化中的酪氨酰自由基功能被 FeIII-FeIV 簇取代。
DOI：
10.1073/pnas.0600603103
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发表时间：
2006
影响因子：
11.1
通讯作者：
A. Gräslund
中科院分区：
文献类型：
--
作者：
N. Voevodskaya;A. Narváez;V. Domkin;E. Torrents;L. Thelander;A. Gräslund
沙眼衣原体核糖核苷酸还原酶(RNR)是由蛋白质R1和R2组成的一类RNR。在蛋白质R2中，含有在其他I类RNR中催化所必需的自由基的酪氨酸残基被苯丙氨酸取代。活性沙眼衣原体RNR使用R2中铁原子簇的Fe(III)-Fe(IV)状态作为催化的引发剂。由(57)Fe取代确定的顺磁性Fe(III)-Fe(IV)状态在持续催化条件下冷冻的样品中变得可检测到的电子自旋共振。它的量取决于催化条件，如孵化温度和R1/R2比。结果表明，Fe(III)-Fe(IV)态的诱导与衣原体RNR的酶活性有关。在此基础上，提出了铁位的反应方案。该方案包括(I)在R2中涉及还原和氧反应的活化循环，以及(Ii)在R1中涉及底物结合和周转的催化循环。
Ribonucleotide reductase (RNR) from Chlamydia trachomatis is a class I RNR composed of proteins R1 and R2. In protein R2, the tyrosine residue harboring the radical that is necessary for catalysis in other class I RNRs is replaced by a phenylalanine. Active C. trachomatis RNR instead uses the Fe(III)-Fe(IV) state of the iron cluster in R2 as an initiator of catalysis. The paramagnetic Fe(III)-Fe(IV) state, identified by (57)Fe substitution, becomes electron spin resonance detectable in samples that are frozen during conditions of ongoing catalysis. Its amount depends on the conditions for catalysis, such as incubation temperature and the R1/R2 ratio. The results link induction of the Fe(III)-Fe(IV) state with enzyme activity of chlamydial RNR. Based on these observations, a reaction scheme is proposed for the iron site. This scheme includes (i) an activation cycle involving reduction and an oxygen reaction in R2 and (ii) a catalysis cycle involving substrate binding and turnover in R1.
影响因子：
56.9
作者：
Stephens, RS;Kalman, S;Davis, RW
通讯作者：
Davis, RW
X簇形成过程中的轻松电子转移以及X在小鼠核糖核苷酸还原酶蛋白R2中产生酪氨酰自由基的动力学能力。
影响因子：
2.9
作者：
Yun,Danny;Krebs,Carsten;Gupta,GovindP;Iwig,DavidF;Huynh,BoiHanh;BollingerJr,JMartin
通讯作者：
BollingerJr,JMartin
影响因子：
56.9
作者：
BOLLINGER, JM;EDMONDSON, DE;STUBBE, J
通讯作者：
STUBBE, J