Curli functional amyloid systems are phylogenetically widespread and display large diversity in operon and protein structure.
Curli functional amyloid systems are phylogenetically widespread and display large diversity in operon and protein structure.
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DOI：
10.1371/journal.pone.0051274
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Nielsen PH
中科院分区：
文献类型：
--
作者：
Dueholm MS;Albertsen M;Otzen D;Nielsen PH
大肠杆菌和肠杆菌目的其他一些成员可以产生功能性淀粉样蛋白，称为卷曲蛋白。这些细胞外原纤维参与生物膜的形成，研究表明，它们可能在感染期间充当毒力因子。目前尚不清楚卷曲纤维是否仅限于肠杆菌目，或者它们是否在细菌遗传学上广泛分布。越来越多的基因组测序的细菌跨越许多系统发育组允许可靠的生物信息学调查的系统发育多样性的卷曲系统。在这里，我们表明，curli系统是遗传学更广泛的比最初假设的，跨越至少四门。因此，卷曲原纤维可能经常遇到的环境以及病原生物膜，这是支持的卷曲基因在公共宏基因组中的识别从不同的栖息地。curli亚基（CsgA/B）同源物的鉴定和比较表明，这些蛋白质允许在其主要蛋白质结构的高度自由度，尽管含有保守的谷氨酰胺，天冬酰胺和甘氨酸残基的紧密间隔的重复区域的模块化结构必须被保留。此外，细菌类群之间curli亚基的操纵子结构的高度变异性表明，curli原纤维可能已经进化到履行特定的功能。在不同的细菌属中也可以看到curli基因的遗传组织的变化。这表明，一些属可能利用替代的调节途径curli表达。Csg蛋白和相应细菌的16 S rRNA基因的系统发育树的比较显示出显着相似的整体地形，表明水平基因转移是一个次要的球员在curli系统的传播。
Escherichia coli and a few other members of the Enterobacteriales can produce functional amyloids known as curli. These extracellular fibrils are involved in biofilm formation and studies have shown that they may act as virulence factors during infections. It is not known whether curli fibrils are restricted to the Enterobacteriales or if they are phylogenetically widespread. The growing number of genome-sequenced bacteria spanning many phylogenetic groups allows a reliable bioinformatic investigation of the phylogenetic diversity of the curli system. Here we show that the curli system is phylogenetically much more widespread than initially assumed, spanning at least four phyla. Curli fibrils may consequently be encountered frequently in environmental as well as pathogenic biofilms, which was supported by identification of curli genes in public metagenomes from a diverse range of habitats. Identification and comparison of curli subunit (CsgA/B) homologs show that these proteins allow a high degree of freedom in their primary protein structure, although a modular structure of tightly spaced repeat regions containing conserved glutamine, asparagine and glycine residues has to be preserved. In addition, a high degree of variability within the operon structure of curli subunits between bacterial taxa suggests that the curli fibrils might have evolved to fulfill specific functions. Variations in the genetic organization of curli genes are also seen among different bacterial genera. This suggests that some genera may utilize alternative regulatory pathways for curli expression. Comparison of phylogenetic trees of Csg proteins and the 16S rRNA genes of the corresponding bacteria showed remarkably similar overall topography, suggesting that horizontal gene transfer is a minor player in the spreading of the curli system.
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影响因子：
3.6
作者：
Nenninger AA;Robinson LS;Hammer ND;Epstein EA;Badtke MP;Hultgren SJ;Chapman MR
通讯作者：
Chapman MR
影响因子：
14.9
作者：
Ludwig, W;Strunk, O;Schleifer, KH
通讯作者：
Schleifer, KH
影响因子：
--
作者：
Kalastavadi T;True HL
通讯作者：
True HL
DOI：
10.1073/pnas.0812143106
发表时间：
2009-01-20
影响因子：
11.1
作者：
Nenninger, Ashley A.;Robinson, Lloyd S.;Hultgren, Scott J.
通讯作者：
Hultgren, Scott J.
影响因子：
82.9
作者：
Herwald, H;Mörgelin, M;Björck, L
通讯作者：
Björck, L