Conservation and diversity of radiation and oxidative stress resistance mechanisms inDeinococcusspecies

Abstract

Deinococcus bacteria are famous for their extreme resistance to ionising radiation and other DNA damage- and oxidative stress-generating agents. More than a hundred genes have been reported to contribute to resistance to radiation, desiccation and/or oxidative stress in Deinococcus radiodurans. These encode proteins involved in DNA repair, oxidative stress defence, regulation and proteins of yet unknown function or with an extracytoplasmic location. Here, we analysed the conservation of radiation resistance-associated proteins in other radiation-resistant Deinococcus species. Strikingly, homologues of dozens of these proteins are absent in one or more Deinococcus species. For example, only a few Deinococcus-specific proteins and radiation resistance-associated regulatory proteins are present in each Deinococcus, notably the metallopeptidase/repressor pair IrrE/DdrO that controls the radiation/desiccation response regulon. Inversely, some Deinococcus species possess proteins that D. radiodurans lacks, including DNA repair proteins consisting of novel domain combinations, translesion polymerases, additional metalloregulators, redox-sensitive regulator SoxR and manganese-containing catalase. Moreover, the comparisons improved the characterisation of several proteins regarding important conserved residues, cellular location and possible protein–protein interactions. This comprehensive analysis indicates not only conservation but also large diversity in the molecular mechanisms involved in radiation resistance even within the Deinococcus genus.

Antioxidant Activities of an Exopolysaccharide (DeinoPol) Produced by the Extreme Radiation-Resistant Bacterium Deinococcus radiodurans

“…Deinococcus spp. have highly diverse and redundant antioxidant defense systems 14,15,32 . The ROS-scavenging system is composed of several lines of enzymatic and non-enzymatic antioxidants such as catalase, peroxidase, superoxide dismutase, lipoic acid, intracellular manganese, pyrroloquinoline quinone (PQQ), and carotenoids 5,9,17,33 .…”

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

“…Deinococcus radiodurans is famous for its extreme resistance to radiation, desiccation, and oxidative stress. The robust resistance results from the combination of multiple strategies, including the efficient repair of broken DNA, especially DNA double‐strand breaks (DSBs), and the protection of various proteins against oxidation . These enhanced DNA repair and antioxidation systems enable D. radiodurans to recover rapidly from extreme environments …”

Functionalized Nanomaterial Assembling and Biosynthesis Using the Extremophile Deinococcus radiodurans for Multifunctional Applications

“…Deinoxanthin (2,1′‐dihydroxy‐3′,4′‐didehydro‐1′,2′‐dihydro‐β, ψ‐caroten‐4‐one, DX) is a tetraterpenoid metabolite identified in the extremophile D. radiodurans to defend against oxidants and ionizing radiation . DX contains 13 conjugated double bonds and multiple hydroxyl groups, which contribute to its strong in vitro antioxidant activity and makes it a potent chemopreventive agent or dietary supplement .…”

“…Extremophiles have been exploited for nanomaterial synthesis and environmental remediation because many unique biological pathways to tolerance for harsh conditions in extremophiles produce durable proteins to create biological factories and allow for greater control of nanomaterial characteristics and maintain the stability of nanomaterials in adverse conditions . Deinococcus radiodurans , a red‐pigmented non‐pathogenic bacterium isolated from an irradiated meat can, is an extreme bacterium well known for its exceptional resistance to stresses, including radiation (15 000 Gy of ionizing radiation without lethality), electrophilic agents, oxidants, desiccation, ultraviolet (UV) light, and DNA damage . The combination of different physiological determinants and well‐regulated molecular mechanisms, including specific proteins, highly condensed nucleoids, efficient antioxidant and DNA repair systems, and protein protection, contribute to the survival strategies of D. radiodurans .…”

“…Deinococcus radiodurans , a red‐pigmented non‐pathogenic bacterium isolated from an irradiated meat can, is an extreme bacterium well known for its exceptional resistance to stresses, including radiation (15 000 Gy of ionizing radiation without lethality), electrophilic agents, oxidants, desiccation, ultraviolet (UV) light, and DNA damage . The combination of different physiological determinants and well‐regulated molecular mechanisms, including specific proteins, highly condensed nucleoids, efficient antioxidant and DNA repair systems, and protein protection, contribute to the survival strategies of D. radiodurans . Therefore, D. radiodurans has been regarded as an optimal model organism to study oxidative stress response, radiation resistance, DNA damage, and DNA repair.…”