The cytochrome bd respiratory oxygen reductases.
The cytochrome bd respiratory oxygen reductases.
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DOI：
10.1016/j.bbabio.2011.06.016
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发表时间：
2011-11
影响因子：
4.3
通讯作者：
Verkhovsky, Michael I.
中科院分区：
文献类型：
--
作者：
Borisov, Vitaliy B.;Gennis, Robert B.;Hemp, James;Verkhovsky, Michael I.
细胞色素BD是一种呼吸性的喹酚：O2氧化还原酶，存在于包括多种病原体在内的许多原核生物中。该酶的主要生物能量功能是通过质子的矢量电荷转移产生质子动力。细胞色素BD的序列与其他呼吸氧还原酶，即血红素-铜氧还原酶或交替氧化酶(AOX)的序列不同。一般来说，细胞色素BD因其对O2的高亲和力和抗氰化物的抑制而值得注意。例如，在大肠杆菌中，细胞色素BD(具体地说，细胞色素BD-I)在O2限制的条件下表达。在BD家族的成员中，有所谓的氰化物不敏感的喹酚氧化酶(CIO)，这种酶通常同名的血红素d的含量很低，但在至少大部分的酶群中，它们的血红素b取代了血红素d。然而，在这一点上，还没有确定序列基序来区分细胞色素BD(具有化学计量补充的血红素d)和一种被指定为CIO的酶。BD-家族的成员可以细分为在亚基I的跨膜螺旋6和7之间包含长的或短的亲水连接的成员，称为Q-环。然而，目前还不清楚这种差异是否有功能上的后果。本文综述了细胞色素BD的生理功能、遗传学、结构和催化性质等方面的研究进展。这篇综述包括对催化循环的中间体的描述，氧还原的建议位置，连接这个活性位置和细菌细胞质的质子通道的证据，以及产生膜电位的分子机制。
Cytochrome bd is a respiratory quinol:O2 oxidoreductase found in many prokaryotes, including a number of pathogens. The main bioenergetic function of the enzyme is the production of a proton motive force by the vectorial charge transfer of protons. The sequences of cytochromes bd are not homologous to those of the other respiratory oxygen reductases, i.e., the heme-copper oxygen reductases or alternative oxidases (AOX). Generally, cytochromes bd are noteworthy for their high affinity for O2 and resistance to inhibition by cyanide. In E. coli, for example, cytochrome bd (specifically, cytochrome bd-I) is expressed under O2-limited conditions. Among the members of the bd-family are the so-called cyanide-insensitive quinol oxidases (CIO) which often have a low content of the eponymous heme d but, instead, have heme b in place of heme d in at least a majority of the enzyme population. However, at this point, no sequence motif has been identified to distinguish cytochrome bd (with a stoichiometric complement of heme d) from an enzyme designated as CIO. Members of the bd-family can be subdivided into those which contain either a long or a short hydrophilic connection between transmembrane helices 6 and 7 in subunit I, designated as the Q-loop. However, it is not clear whether there is a functional consequence of this difference. This review summarizes current knowledge on the physiological functions, genetics, structural and catalytic properties of cytochromes bd. Included in this review are descriptions of the intermediates of the catalytic cycle, the proposed site for the reduction of O2, evidence for a proton channel connecting this active site to the bacterial cytoplasm, and the molecular mechanism by which a membrane potential is generated.
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DOI：
10.1073/pnas.0608794104
发表时间：
2007-02-20
影响因子：
11.1
作者：
Belevich, Ilya;Bloch, Dmitry A.;Verkhovsky, Michael I.
通讯作者：
Verkhovsky, Michael I.
影响因子：
64.8
作者：
Baughn, AD;Malamy, MH
通讯作者：
Malamy, MH
影响因子：
3.2
作者：
Becker, S;Holighaus, G;Unden, G
通讯作者：
Unden, G
影响因子：
3.5
作者：
AVETISYAN, AV;BOGACHEV, AV;SKULACHEV, VP
通讯作者：
SKULACHEV, VP
影响因子：
3.5
作者：
Belevich, I;Borisov, VB;Verkhovsky, MI
通讯作者：
Verkhovsky, MI