Evidence of positive Darwinian selection in Omp85, a highly conserved bacterial outer membrane protein essential for cell viability
Evidence of positive Darwinian selection in Omp85, a highly conserved bacterial outer membrane protein essential for cell viability
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DOI：
10.1007/s00239-004-0194-5
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发表时间：
2005-02-01
影响因子：
3.9
通讯作者：
McInerney, JO
中科院分区：
文献类型：
--
作者：
Fitzpatrick, DA;McInerney, JO
Omp85是一种高度保守的外膜蛋白，存在于所有革兰氏阴性菌中。它对细菌细胞的生存至关重要，在其他外膜蛋白定位和折叠到细菌外膜中起着不可或缺的作用。我们采用最大似然法和最大简约法检测了10种三角洲变形菌中Omp85同源物的达尔文选择阳性证据，并确定了14个氨基酸位点显示受适应性进化影响的证据。有趣的是，除了一个位点外，所有位点都集中在蛋白质的表面环中，这些环最有可能与宿主免疫反应或周围环境相互作用。另外，蛋白质跨膜区域内的氨基酸被发现处于纯化选择下，这很可能是结构限制的结果。
Omp85 is a highly conserved outer membrane protein found in all gram-negative bacteria. It is essential for bacterial cell viability and plays an integral function in the positioning and folding of other outer membrane proteins into the bacterial outer membrane. We have employed a maximum likelihood and a maximum parsimony approach to detect evidence of positive Darwinian selection in Omp85 homologues from 10 delta-proteobacteria and have identified 14 amino acid sites that show evidence of being under the influence of adaptive evolution. Interestingly all sites bar one are concentrated within surface loops of the protein that most likely interact with host immune response or the surrounding environment. Alternatively amino acids within membrane-spanning regions of the protein are found to be under purifying selection most likely as a result of structural constraints.