Protein surface amino acid compositions distinctively differ between thermophilic and mesophilic bacteria
Protein surface amino acid compositions distinctively differ between thermophilic and mesophilic bacteria
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DOI：
10.1006/jmbi.2001.4718
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发表时间：
2001-06-15
影响因子：
5.6
通讯作者：
Nishikawa, K
中科院分区：
文献类型：
--
作者：
Fukuchi, S;Nishikawa, K
嗜热菌蛋白质的一个众所周知的观察结果是氨基酸组成的偏差，其中带电残基大量存在，极性残基很少。另一方面，据报道，蛋白质的分子表面适应其亚细胞位置，在氨基酸组成方面。因此，可以合理地预期嗜热菌和嗜温菌蛋白质之间的氨基酸组成差异在蛋白质表面上比在内部大得多。我们进行了系统的比较嗜热菌和嗜温菌的蛋白质，在蛋白质表面和内部的氨基酸组成，以及整个氨基酸链，通过使用基因组计划的序列信息。嗜热蛋白质的氨基酸组成与中温蛋白质的氨基酸组成有明显的差异，其中以蛋白质表面组成的差异最为明显。与表面组成相反，内部组成在嗜热蛋白和嗜温蛋白之间没有区别。对空间位置相近的氨基酸对的频率也进行了分析，显示出与单个氨基酸组成相同的趋势。有趣的是，来自嗜温细菌的胞外蛋白质显示出与嗜热蛋白质相反的趋势（即带电残基的数量减少并且富含极性残基）。来自真核生物的核蛋白，已知其富含正电荷，整体上显示出与嗜热菌不同的组成。这些结果表明，嗜热蛋白的氨基酸组成的偏差是由于蛋白质表面的残基，这可能是由极端环境的约束。(C)北京：科学出版社.
One of the well-known observations of proteins from thermophilic bacteria is the bias of the amino acid composition in which charged residues are present in large numbers, and polar residues are scarce. On the other hand, it has been reported that the molecular surfaces of proteins are adapted to their subcellular locations, in terms of the amino acid composition. Thus, it would be reasonable to expect that the differences in the amino acid compositions between proteins of thermophilic and mesophilic bacteria would be much greater on the protein surface than in the interior. We performed systematic comparisons between proteins from thermophilic bacteria and mesophilic bacteria, in terms of the amino acid composition of the protein surface and the interior, as well as the entire amino acid chains, by using sequence information from the genome projects. The biased amino acid composition of thermophilic proteins was confirmed, and the differences from those of mesophilic proteins were most obvious in the compositions of the protein surface. In contrast to the surface composition, the interior composition was not distinctive between the thermophilic and mesophilic proteins. The frequency of the amino acid pairs that are closely located in the space was also analyzed to show the same trend of the single amino acid compositions. Interestingly, extracellular proteins from mesophilic bacteria showed an inverse trend against thermophilic proteins (i.e. a reduced number of charged residues and rich in polar residues). Nuclear proteins from eukaryotes, which are known to be abundant in positive charges, showed different compositions as a whole from the thermophiles. These results suggest that the bias of the amino acid composition of thermophilic proteins is due to the residues on the protein surfaces, which may be constrained by the extreme environment. (C) 2001 Academic Press.