The S-layer Protein DR_2577 Binds Deinoxanthin and under Desiccation Conditions Protects against UV-Radiation in Deinococcus radiodurans.
The S-layer Protein DR_2577 Binds Deinoxanthin and under Desiccation Conditions Protects against UV-Radiation in Deinococcus radiodurans.
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DOI：
10.3389/fmicb.2016.00155
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发表时间：
2016
影响因子：
5.2
通讯作者：
Piano D
中科院分区：
文献类型：
--
作者：
Farci D;Slavov C;Tramontano E;Piano D
耐辐射球菌具有令人费解的能力，可以承受广泛的极端条件，包括高剂量的紫外线辐射和深度干燥。这种细菌被一层表层(S层)包围，该表层由几种蛋白质的规则重复组成，组装形成一个准晶结构。在这里，我们报道了S层的一个主要成分DR2577基因的缺失导致了紫外线抗性的下降，特别是在干燥的细胞中。此外，我们还发现DR_2577蛋白与类胡萝卜素脱氧素结合，类胡萝卜素是该细菌特有的强保护性抗氧化剂。对脱氧核黄质-DR_2577复合体的进一步光谱表征揭示了DR_2577的保护作用。我们认为，特别是在干燥情况下，S层屏蔽了细菌免受入射紫外线的影响，可以作为抵御紫外线辐射的第一道屏障。
Deinococcus radiodurans has the puzzling ability to withstand over a broad range of extreme conditions including high doses of ultraviolet radiation and deep desiccation. This bacterium is surrounded by a surface layer (S-layer) built of a regular repetition of several proteins, assembled to form a paracrystalline structure. Here we report that the deletion of a main constituent of this S-layer, the gene DR_2577, causes a decrease in the UVC resistance, especially in desiccated cells. Moreover, we show that the DR_2577 protein binds the carotenoid deinoxanthin, a strong protective antioxidant specific of this bacterium. A further spectroscopical characterization of the deinoxanthin-DR_2577 complex revealed features which could suggest a protective role of DR_2577. We propose that, especially under desiccation, the S-layer shields the bacterium from incident ultraviolet light and could behave as a first lane of defense against UV radiation.