The S-layer Protein DR_2577 Binds Deinoxanthin and under Desiccation Conditions Protects against UV-Radiation in Deinococcus radiodurans

Abstract

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.

Succinylome Analysis Reveals the Involvement of Lysine Succinylation in the Extreme Resistance of Deinococcus radiodurans

“…Two important reactive oxygen species (ROS) scavengers, KatE and SodA, had more than one succinylation site, which are highly expressed in D. radiodurans . SlpA, a major S‐layer protein essential for binding of the antioxidant carotenoid deinoxanthin, had two succinylation sites . Moreover, proteins involved in distinct DNA repair pathways were found to be succinylated.…”

Insights into Ionizing-Radiation-Resistant Bacteria S-Layer Proteins and Nanobiotechnology for Bioremediation of Hazardous and Radioactive Waste

“…Using electron microscopy, Rothfuss et al [8] have identified five layers: (1) the inner membrane, (2) the peptidoglycan cell wall, (3) the interstitial layer, (4) Hpi and the backing layer, and (5) the carbohydrate coat. D. radiodurans envelope has an unusual structure and composition with the outermost surface of this formation is the "pink envelope" containing carbohydrates, proteins, carotenoid (deinoxanthin [7]), lipids, and most likely the outer membrane [8]. SlpA (DR_2577) and Hpi (DR_2508) are the most abundant components responsible for the envelope maintaining [35].…”

“…The SLH domain of SlpA was shown to bind deinococcal peptidoglycan-containing cell wall sacculi [45]. Indeed, it has [8], PilQ (DR_0774) as a component related with the S-layer [35] and the predicted association between: (i) SlpA and deinococcal peptidoglycan-containing cell wall [45], (ii) SlpA and Hpi [45], and (iii) SlpA and deinoxanthin [7]. The association of SlpA with peptidoglycan on one side and Hpi on the other localizes this protein in the "interstitial" layer of the deinoccocal cell wall [45].…”

“…Since the outer envelope-regular crystalline highly porous (glycol)protein meshworks ((s(urface)-layers)-of IRRB ( [7,8] and references therein) represents the first front that might encounter HRW and damaging radiation, it is expected to possess pertinent characteristics such as the ability to interact with actinides. These latter (e.g., americium-241 ( 241 Am), neptunium-237 ( 237 Np), plutonium-241 ( 241 Pu), and thorium-230 ( 230 Th)) might also be present in most radioactive wastes; however, uranium-238 ( 238 U) is the priority pollutant ( [9] and references therein).…”

Resposta biológica de <i>Pseudomonas syringae</i> ao ambiente atmosférico.

“…Foi estimado que este ganho de eficiência contribuiu para uma economia de ao menos 100 milhões de dólares por ano em custos energéticos em estações de esqui canadenses (SKIRVIN et al, 2000). O uso apropriado de produtos assim foi considerado seguro nos âmbitos de proteção ambiental (GOODNOW et al, 1990;SKIRVIN et al, 2000) e de saúde humana (LAGRIFFOUL et al, 2010), ainda que alguns autores apontem possíveis impactos negativos à vegetação (RIXEN; STOECKLI; AMMANN, 2003) e a comunidades de fungos no solo (FIORE et al, 2008).…”