Microbial genome analyses: Comparative transport capabilities in eighteen prokaryotes
Microbial genome analyses: Comparative transport capabilities in eighteen prokaryotes
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DOI：
10.1006/jmbi.2000.3961
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发表时间：
2000-08-04
影响因子：
5.6
通讯作者：
Saier, MH
中科院分区：
文献类型：
--
作者：
Paulsen, IT;Nguyen, L;Saier, MH
在这里，我们提出了一个全面的分析溶质转运系统内编码的18个原核生物的基因组完全测序。这些生物体包括四种革兰氏阳性细菌，七种革兰氏阴性细菌，两种螺旋体，一种蓝细菌和四种古细菌。根据膜蛋白的拓扑结构，将已知的转运系统分为76个家族，包括4个通道蛋白家族、4个初级转运蛋白家族、54个次级转运蛋白家族、6个组转运蛋白家族和8个未分类的转运蛋白家族。这些家庭进行了分析，其蛋白质成员的旁系同源和直系同源关系，其组成转运蛋白的底物特异性和它们的分布在每一个研究的18种生物。这些家族从有数百个成员的大超家族到只有一个或几个成员的小家族不等。转运模式通常与能量产生的主要机制相关，次级转运蛋白相对于初级转运蛋白的数量大致与细胞中初级H+和Na+泵的总数成比例。磷酸转移酶系统在分析的细菌中不像以前认为的那样普遍（14种细菌中只有6种通过该系统运输糖），并且在古细菌和真核生物中完全缺乏。大肠杆菌的转运能力非常广泛，因此，在膜转运水平上，似乎不能代表迄今为止测序的细菌。与大多数细菌相比，大肠杆菌和螺旋体表现出较少的具有多个跨膜片段的蛋白质和较少的净转运蛋白。这些结果提供了深入了解运输的相关性，原核生物的整体生理。(C)北京大学出版社.
Here, we present a comprehensive analysis of solute transport systems encoded within the completely sequenced genomes of 18 prokaryotic organisms. These organisms include four Gram-positive bacteria, seven Gram-negative bacteria, two spirochetes, one cyanobacterium and four archaea. Membrane proteins are analyzed in terms of putative membrane topology, and the recognized transport systems are classified into 76 families, including four families of channel proteins, four families of primary carriers, 54 families of secondary carriers, six families of group translocators, and eight unclassified families. These families are analyzed in terms of the paralogous and orthologous relationships of their protein members, the substrate specificities of their constituent transporters and their distributions in each of the 18 organisms studied. The families vary from large superfamilies with hundreds of represented members, to small families with only one ora few members. The mode of transport generally correlates with the primary mechanism of energy generation, and the numbers of secondary transporters relative to primary transporters are roughly proportional to the total numbers of primary H+ and Na+ pumps in the cell. The phosphotransferase system is less prevalent in the analyzed bacteria than previously thought (only six of 14 bacteria transport sugars via this system) and is completely lacking in archaea and eukaryotes. Escherichia coli is shown to be exceptionally broad in its transport capabilities and therefore, at a membrane transport level, does not appear representative of the bacteria thus far sequenced. Archaea and spirochetes exhibit fewer proteins with multiple transmembrane segments and fewer net transporters than most bacteria. These results provide insight into the relevance of transport to the overall physiology of prokaryotes. (C) 2000 Academic Press.