Research on the metabolic engineering of the direct oxidation pathway for extraction of phosphate from ore has generated preliminary evidence for PQQ biosynthesis in Escherichia coli as well as a possible role for the highly conserved region of quinoprote
Research on the metabolic engineering of the direct oxidation pathway for extraction of phosphate from ore has generated preliminary evidence for PQQ biosynthesis in Escherichia coli as well as a possible role for the highly conserved region of quinoprote
复制标题
从矿石中提取磷酸盐的直接氧化途径的代谢工程研究为大肠杆菌中 PQQ 生物合成以及 quinoprote 高度保守区域的可能作用提供了初步证据
DOI：
10.1016/s1570-9639(03)00067-0
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Brown,Jacquelyn
中科院分区：
文献类型：
--
作者：
Goldstein,Alan;Lester,Trevor;Brown,Jacquelyn
一些细菌溶解难溶性磷酸钙（CaP）的能力被称为“矿物磷酸盐增溶”（MPS）。由于大多数微生物和植物必须通过膜运输吸收P，因此将CaP生物转化为可溶性磷酸盐被认为是全球P循环的重要组成部分。在许多革兰氏阴性细菌中，通过直接氧化途径在周质中产生的强有机酸已被证明可以溶解邻近环境中的CaP。因此，醌蛋白葡萄糖脱氢酶（PQQGDH）可能在许多土壤细菌的生理生态中起作用。人们对使用MPS细菌进行磷矿石（取代的氟磷灰石）的工业生物处理或甚至直接接种土壤作为类似于固氮的“生物肥料”感兴趣。我们的实验室花了20年时间研究上级MPS细菌。在合适的E.大肠杆菌的遗传背景可以通过功能互补“捕获”这些细菌的PQQ或GDH基因。在为PQQ基因设置“陷阱”的过程中，我们已经鉴定了在大肠杆菌中明显诱导PQQGDH活性的DNA片段。与已知的PQQ基因没有序列同源性。这些数据表明，E.大肠杆菌可能有一个替代的，可诱导的PQQ生物合成途径。最后，一种新的蛋白质工程策略，以增加PQQGDH的催化速率已经出现，并将进行讨论。
The ability of some bacteria to dissolve poorly soluble calcium phosphates (CaPs) has been termed ‘mineral phosphate solubilizing’ (MPS). Since most microorganisms and plants must assimilate P via membrane transport, biotransformation of CaP into soluble phosphate is considered an essential component of the global P cycle. In many Gram-negative bacteria, strong organic acids produced in the periplasm via the direct oxidation pathway have been shown to dissolve CaP in the adjacent environment. Therefore, the quinoprotein glucose dehydrogenase (PQQGDH) may function in the ecophysiology of many soil bacteria. There is interest in using MPS bacteria for industrial bioprocessing of rock phosphate ore (a substituted fluroapatite) or even for direct inoculation of soils as a ‘biofertilizer’ analogous to nitrogen fixation. Our laboratory has spent 20 years studying superior MPS bacteria. Screening genomic libraries in the appropriate E. coli genetic background can ‘trap’ PQQ or GDH genes from these bacteria via functional complementation. In setting the ‘trap’ for PQQ genes, we have identified DNA fragments that apparently induce PQQGDH activity in E. coli with no sequence homology to known PQQ genes. These data suggest that E. coli may have an alternative, inducible PQQ biosynthesis pathway. Finally, a novel protein engineering strategy to increase the catalytic rate of PQQGDH has emerged and will be discussed.