General N-and O-Linked Glycosylation of Lipoproteins in Mycoplasmas and Role of Exogenous Oligosaccharide.
General N-and O-Linked Glycosylation of Lipoproteins in Mycoplasmas and Role of Exogenous Oligosaccharide.
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DOI：
10.1371/journal.pone.0143362
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Dybvig K
中科院分区：
文献类型：
--
作者：
Daubenspeck JM;Jordan DS;Simmons W;Renfrow MB;Dybvig K
支原体缺乏细胞壁、鞭毛、菌毛和其他胞外附属物，并且仅具有单一膜，这使得支原体结构简单，是研究糖缀合物的理想模式生物。大多数物种的基因组约为800 kb，编码的蛋白质很少，预计在糖生物学中发挥作用。鼠病原体关节炎支原体和肺支原体仅具有注释为编码糖基转移酶但合成糖脂、多糖和糖蛋白的单个基因。此前，已有证据表明M.关节炎通过O-键糖基化表面脂蛋白。在目前的研究中，O-连接的糖蛋白在M.发现肺支原体和两种支原体也在天冬酰胺和谷氨酰胺残基处具有N-连接聚糖。蛋白质糖基化发生在表面暴露的脂蛋白上的许多位点，没有明显的氨基酸序列特异性。肺炎支原体的脂蛋白也是糖基化的。糖基化依赖于宿主寡糖的糖苷键。据我们所知，在革兰氏阳性菌中以前没有描述过N-连接的糖蛋白，革兰氏阳性菌是与支原体遗传学相关的生物体。研究结果表明，支原体细胞表面是严重糖基化与支原体-宿主相互作用的调制的影响。
The lack of a cell wall, flagella, fimbria, and other extracellular appendages and the possession of only a single membrane render the mycoplasmas structurally simplistic and ideal model organisms for the study of glycoconjugates. Most species have genomes of about 800 kb and code for few proteins predicted to have a role in glycobiology. The murine pathogens Mycoplasma arthritidis and Mycoplasma pulmonis have only a single gene annotated as coding for a glycosyltransferase but synthesize glycolipid, polysaccharide and glycoproteins. Previously, it was shown that M. arthritidis glycosylated surface lipoproteins through O-linkage. In the current study, O-linked glycoproteins were similarly found in M. pulmonis and both species of mycoplasma were found to also possess N-linked glycans at residues of asparagine and glutamine. Protein glycosylation occurred at numerous sites on surface-exposed lipoproteins with no apparent amino acid sequence specificity. The lipoproteins of Mycoplasma pneumoniae also are glycosylated. Glycosylation was dependent on the glycosidic linkages from host oligosaccharides. As far as we are aware, N-linked glycoproteins have not been previously described in Gram-positive bacteria, the organisms to which the mycoplasmas are phylogenetically related. The findings indicate that the mycoplasma cell surface is heavily glycosylated with implications for the modulation of mycoplasma-host interactions.