Novel functions of peroxiredoxin Q fromDeinococcus radioduransR1 as a peroxidase and a molecular chaperone

Abstract

Deinococcus radiodurans R1 is extremely resistant to ionizing radiation and oxidative stress. In this study, we characterized DR0846, a candidate peroxiredoxin in D. radiodurans . DR0846 is a peroxiredoxin Q containing two conserved cysteine residues. DR0846 exists mainly in monomeric form with an intramolecular disulfide bond between the two cysteine residues. We found that DR0846 functions as a molecular chaperone as well as a peroxidase. A mutational analysis indicates that the two cysteine residues are essential for enzymatic activity. A double‐deletion mutant lacking DR0846 and catalase DR1998 exhibits decreased oxidative and heat shock stress tolerance with respect to the single mutants or the wild‐type cells. These results suggest that DR0846 contributes to resistance against oxidative and heat stresses in D. radiodurans .

Thiol Reductases in Deinococcus Bacteria and Roles in Stress Tolerance

“…Consistently, it was reported that a Deinococcus geothermalis mutant lacking the cystine importer system, which is a source of thiols, was more sensitive to an H 2 O 2 treatment [21]. Some studies based on biochemical, pharmacological, or genetic approaches characterised the Trx system in Deinococcus [22][23][24] and indicated that it likely plays an essential role in responses to oxidative stress [25,26]. In a previous review describing Deinococcus antioxidant systems [3], the main TR families were listed, revealing that this bacterial genus possesses a complete Trx system, including a relatively high number of TRs related to Trxs and Prxs.…”

“…Cho et al [25] investigated the expression levels of the three bcp genes in D. radiodurans exposed to oxidative stress generated by H 2 O 2 or subjected to gamma irradiation. DR_0846 was strongly induced by both treatments, while the expression of DR_1209 was moderately increased by the peroxide, and that of DR_1208 was substantially triggered by irradiation.…”

“…The D. radiodurans DR_0846 BCP protein has been further characterised with regard to its activity and physiological function [25]. The recombinant protein exhibits peroxidase activity towards H 2 O 2 and holdase chaperone activity when measuring thermal-induced aggregation of a heat-sensitive substrate.…”

A Novel Thioredoxin-Dependent Peroxiredoxin (TPx-Q) Plays an Important Role in Defense Against Oxidative Stress and Is a Possible Drug Target in Babesia microti

“…Su et al (30) found that TPx-Q functions as molecular chaperone and peroxidase. Cho et al (58) first reported that Prx Q of Deinococcus radiodurans R1 is a monomeric atypical 2-Cys Prx and has dual activity as peroxidase and a molecular chaperone. However, the molecular chaperones function of BmTPx-Q needs to be further studied.…”

Atypical Bacilliredoxin AbxC Plays a Role in Responding to Oxidative Stress in Radiation-Resistant Bacterium Deinococcus radiodurans

“…DR_A0164 is reduced by D. radiodurans Trx reductase (TrxR; DR_1982), which can utilize only NADPH for activity [12]. DR_0846 is a Trx-dependent PrxQ, a homolog of bacterioferritin comigratory protein (BCP), which contains the two closely situated Cys residues (CXXXXC), and it functions as a molecular chaperone as well as a peroxidase [13].…”