Structure and functions of a very small tetraheme protein -Molecular mechanism of bioremediation-

许多Shewanella物种中最引人注目的特征可能会减少不稳定的金属氧化物、铁和锰。S. S.无核应变MR 1被认为是一种特殊的金属氧化物（铁和锰）的有机体，并表明将金属氧化物减少到有机碳的氧化中。Shewanella物种在不同的电子接收器中生长的可能性，从+0.8 V （氧）到大约0 （元素硫）的作用是，这种细菌可以通过活动和/或电子传输链的组成来调整增长条件。细胞色素在希瓦内拉是富集的，并且在金属氧化物的减少中被隐含。四烯蛋白、细胞色素C-D23-D2的redox行为在这项工作中进行了调查。宏观和微观redox潜力被确定为pH值9。Although they are low in comparison with other cytochrome， they are high than the redox potentials of cytochrome D23イエD2 from Desulfovibrio vulgaris Miyazaki F （DvMF）。DvMF细胞色素C-D23-D2基因成功地表达在一个功能性航空器、Shewanella无核可膜MR-I、低于代谢、微有氧和有氧条件与良好的年份。A衍生出的宽主机范围等离子体pRK 415含有细胞色素C-D23-D2，来自DMF的基因被用于S的转变。putrefaciens MR-1，在Holocytochrome C-D23-D2的生产中的结果，它是由D生产的。vulgaris Miyazaki F.

The most remarkable characteristic of many Shewanella species is their ability to reduce insoluble metal oxides, including iron, and manganese. S. putrefaciens strain MR1 was specifically isolated as a metal oxide (iron and manganese) reducing organism, and shown to couple the reduction of metal oxides to the oxidation of organic carbon. The ability of Shewanella species to grow with a variety of different electron acceptors having redox potentials from +0.8 V (oxygen) to about 0 (elemental sulfur) implies that this bacterium is able to adjust to growth conditions through changes in the activity and/or the composition of the electron transport chain. Cytochromes are abundant in Shewanella and have been implicated in the reduction of metal oxides. The redox behavior of a tetraheme protein, cytochrome cィイD23ィエD2 was investigated in this work. The macroscopic and microscopic redox potentials were determined at pH 9. Although they are low in comparison with other cytochromes, they are higher than the redox potentials of cytochrome cィイD23ィエD2 from Desulfovibrio vulgaris Miyazaki F (DvMF). DvMF cytochrome cィイD23ィエD2 gene was successfully expressed in a facultative aerobe, Shewanella putrefaciens MR-I, under anaerobic, microaerobic, and aerobic conditions with good yields. A derivative of the broad-host-range plasmid pRK415 containing the cytochrome cィイD23ィエD2, genes from DvMF was used for transformation of S. putrefaciens MR-1, resulting in the production of holocytochrome cィイD23ィエD2 that was indistinguishable from that produced by D. vulgaris Miyazaki F.