Lipoteichoic acid of Streptococcus oralis Uo5: a novel biochemical structure comprising an unusual phosphorylcholine substitution pattern compared to Streptococcus pneumoniae
Lipoteichoic acid of Streptococcus oralis Uo5: a novel biochemical structure comprising an unusual phosphorylcholine substitution pattern compared to Streptococcus pneumoniae
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DOI：
10.1038/srep16718
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发表时间：
2015-11-18
影响因子：
4.6
通讯作者：
Denapaite, Dalia
中科院分区：
文献类型：
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作者：
Gisch, Nicolas;Schwudke, Dominik;Denapaite, Dalia
缓症链球菌群的成员具有磷壁酸（TA）作为其细胞壁的组成部分，这在革兰氏阳性细菌中是独特的。脂磷壁酸（LTA）和壁磷壁酸两者通过相同的生物合成途径形成，具有高度复杂性并且含有磷酸胆碱（P-Cho）残基。这些残基作为胆碱结合蛋白（CBPs）的锚，其中一些已被确定为人类病原体肺炎链球菌的毒力因子。我们研究了其近亲口腔链球菌的LTA结构。分析表明，S.口腔链球菌Uo 5 LTA具有与肺炎球菌LTA（pnLTA）相似的总体结构，并且可以被认为是IV型LTA的亚型。其结构复杂性甚至高于pnLTA，并且其组成在碳水化合物部分的数量和类型、残基间连接性以及特别是P-Cho取代模式方面不同。在这里，我们报告的发生的糖部分取代两个P-Cho残基，这是独特的，但在细菌衍生的表面碳水化合物。最后，我们可以将观察到的S之间的重要结构变化联系起来。oralis和S. pneumoniae LTA与它们的TA生物合成的不同酶库相关联。
Members of the Mitis group of streptococci possess teichoic acids (TAs) as integral components of their cell wall that are unique among Gram-positive bacteria. Both, lipoteichoic (LTA) and wall teichoic acid, are formed by the same biosynthetic pathway, are of high complexity and contain phosphorylcholine (P-Cho) residues. These residues serve as anchors for choline-binding proteins (CBPs), some of which have been identified as virulence factors of the human pathogen Streptococcus pneumoniae. We investigated the LTA structure of its close relative Streptococcus oralis. Our analysis revealed that S. oralis Uo5 LTA has an overall architecture similar to pneumococcal LTA (pnLTA) and can be considered as a subtype of type IV LTA. Its structural complexity is even higher than that of pnLTA and its composition differs in number and type of carbohydrate moieties, inter-residue connectivities and especially the P-Cho substitution pattern. Here, we report the occurrence of a saccharide moiety substituted with two P-Cho residues, which is unique as yet in bacterial derived surface carbohydrates. Finally, we could link the observed important structural variations between S. oralis and S. pneumoniae LTA to the divergent enzymatic repertoire for their TA biosynthesis.