Enzymatic Antioxidant Signatures in Hyperthermophilic Archaea

Abstract

To fight reactive oxygen species (ROS) produced by both the metabolism and strongly oxidative habitats, hyperthermophilic archaea are equipped with an array of antioxidant enzymes whose role is to protect the biological macromolecules from oxidative damage. The most common ROS, such as superoxide radical (O2−.) and hydrogen peroxide (H2O2), are scavenged by superoxide dismutase, peroxiredoxins, and catalase. These enzymes, together with thioredoxin, protein disulfide oxidoreductase, and thioredoxin reductase, which are involved in redox homeostasis, represent the core of the antioxidant system. In this review, we offer a panorama of progression of knowledge on the antioxidative system in aerobic or microaerobic (hyper)thermophilic archaea and possible industrial applications of these enzymes.

A large scale, multiple genome comparison of acidophilic Archaea (pH ≤ 5.0) extends our understanding of oxidative stress responses in polyextreme environments

“…MAR08-33, this forms a separated clade with other Euryarchaeota organisms (not acidophiles) and some Deltaproteobacteria (Figure S3). The low presence in Archaea has been reported previously, as organisms that have SOD usually do not have catalases [21] and as previously discussed we identified SOD in most acidophilic genomes with the exception of Aciduliprofundum. The result of mixed origin clades in the phylogenetic reconstruction where Archaea and Bacteria share the same clade suggests that HGT between domains could play a major role in the evolution of catalases.…”

“…The wide conservation across organisms of superoxide dismutase, peroxiredoxin, and rubrerythrin in both anaerobic and aerobic organisms, could suggest an ancestral origin of these proteins [82,106,107], and that they were evolved in similar environments to the early LUCA in response to local concentrations of oxygen before the GOE [108]. It has been previously reported that multiple mechanisms for oxidative stress response are found in hyperthermophiles [21] and we identified a similar pattern in acidophiles with no major differences across lifestyles (such as aerobic versus anaerobic or thermophiles versus mesophiles). Instead, the distribution of oxidative stress response mechanisms present in each organism seems to be largely determined by phylogeny.…”

“…The archaeal domain comprises a wide range of organisms, many of which thrive in environments that are considered polyextreme, such as extremely high temperatures, low and high pHs and high salinity conditions [18][19][20]. Within these groups, stress response mechanisms have been described for hyperthermophiles [21] that constitute the majority of all identified Archaeal organisms. Acidophiles, are commonly defined as organisms that grow optimally at pH lower than 5 [22,23].…”

Microorganisms: A Potential Source of Bioactive Molecules for Antioxidant Applications

“…Later on, it was reported from other haloarchaea, including Halobacterium saccharovorum , Haloarcula ( Halobacterium ) marismortui , Haloarcula californiae , Halococcus sp. LS-1), and Haloferax ( Halobacterium ) volcanii [ 77 , 78 ]. Bacterioferritin comigratory protein 1 (Bcp1) belongs to the Prx family, isolated from hyperthermophilic archaeon Sulfolobus solfataricus , which has been characterized as an antioxidant that inhibits H 2 O 2 -induced apoptosis in H9c2 rat cardiomyoblast cells [ 79 ].…”

Unlocking Survival Mechanisms for Metal and Oxidative Stress in the Extremely Acidophilic, Halotolerant Acidihalobacter Genus

“…Rbr is a member of the ferritin-like superfamily [71] and has been implicated in stress survival in many bacteria [72] and archaea [73]. It has been experimentally verified to function as a scavenger of ROS using a di-iron center to reduce H 2 O 2 and organic hyperperoxide to water [74][75][76][77][78].…”