The mucin-degradation strategy of Ruminococcus gnavus: The importance of intramolecular trans-sialidases.
The mucin-degradation strategy of Ruminococcus gnavus: The importance of intramolecular trans-sialidases.
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DOI：
10.1080/19490976.2016.1186334
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发表时间：
2016-07-03
期刊：
影响因子：
12.2
通讯作者：
Juge N
中科院分区：
文献类型：
--
作者：
Crost EH;Tailford LE;Monestier M;Swarbreck D;Henrissat B;Crossman LC;Juge N
我们之前在肠道共生体疣状瘤胃球菌 ATCC 29149 中鉴定并鉴定了一种分子内转唾液酸酶（IT-唾液酸酶），该酶与该菌株在粘蛋白上生长的能力有关。在这项工作中，我们获得并分析了从健康个体中分离出的另一种 R. gnavus 粘蛋白降解剂 ATCC 35913 的基因组序列草案。 ATCC 29149 和 ATCC 35913 菌株的转录组学分析证实，R. gnavus 用于粘蛋白降解的策略集中于利用末端粘蛋白聚糖。 R. gnavus ATCC 35913 还编码一种预测的 IT-唾液酸酶，并含有一个专门用于唾液酸利用的 Nan 簇。我们发现，当菌株在粘蛋白存在下生长时，Nan 簇被上调。此外，我们证明两种 R. gnavus 菌株都能够以 2,7-anyHydro-Neu5Ac（IT-唾液酸酶转糖基化产物）作为唯一碳源生长。总而言之，这些数据进一步支持了这样的假设：表达 IT-唾液酸酶的肠道微生物通过获取和转化营养来源以使其自身受益，为共生细菌（如 R. gnavus）提供营养竞争优势。
We previously identified and characterized an intramolecular trans-sialidase (IT-sialidase) in the gut symbiont Ruminococcus gnavus ATCC 29149, which is associated to the ability of the strain to grow on mucins. In this work we have obtained and analyzed the draft genome sequence of another R. gnavus mucin-degrader, ATCC 35913, isolated from a healthy individual. Transcriptomics analyses of both ATCC 29149 and ATCC 35913 strains confirmed that the strategy utilized by R. gnavus for mucin-degradation is focused on the utilization of terminal mucin glycans. R. gnavus ATCC 35913 also encodes a predicted IT-sialidase and harbors a Nan cluster dedicated to sialic acid utilization. We showed that the Nan cluster was upregulated when the strains were grown in presence of mucin. In addition we demonstrated that both R. gnavus strains were able to grow on 2,7-anyhydro-Neu5Ac, the IT-sialidase transglycosylation product, as a sole carbon source. Taken together these data further support the hypothesis that IT-sialidase expressing gut microbes, provide commensal bacteria such as R. gnavus with a nutritional competitive advantage, by accessing and transforming a source of nutrient to their own benefit.