Three HRDC Domains Differentially Modulate Deinococcus radiodurans RecQ DNA Helicase Biochemical Activity

Killoran, Michael P.; Keck, James L.

doi:10.1074/jbc.m600097200

Cited by 32 publications

(52 citation statements)

References 49 publications

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“…8). The D. radiodurans RecQ helicase contains three C-terminal HRD (helicaseRNase D) domains also found in Neisseria meningitidis and Neisseria gonorrhoeae, which are critical for high-affinity DNA binding and DNA unwinding (261,293). Its involvement in DNA repair in D. radiodurans remains to be elucidated.…”

Section: Recombinational Processes In D Radiodurans Dna Repairmentioning

confidence: 99%

Oxidative Stress Resistance inDeinococcus radiodurans

Slade

Radman

2011

Microbiol Mol Biol Rev

646

639

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SUMMARY Deinococcus radiodurans is a robust bacterium best known for its capacity to repair massive DNA damage efficiently and accurately. It is extremely resistant to many DNA-damaging agents, including ionizing radiation and UV radiation (100 to 295 nm), desiccation, and mitomycin C, which induce oxidative damage not only to DNA but also to all cellular macromolecules via the production of reactive oxygen species. The extreme resilience of D. radiodurans to oxidative stress is imparted synergistically by an efficient protection of proteins against oxidative stress and an efficient DNA repair mechanism, enhanced by functional redundancies in both systems. D. radiodurans assets for the prevention of and recovery from oxidative stress are extensively reviewed here. Radiation- and desiccation-resistant bacteria such as D. radiodurans have substantially lower protein oxidation levels than do sensitive bacteria but have similar yields of DNA double-strand breaks. These findings challenge the concept of DNA as the primary target of radiation toxicity while advancing protein damage, and the protection of proteins against oxidative damage, as a new paradigm of radiation toxicity and survival. The protection of DNA repair and other proteins against oxidative damage is imparted by enzymatic and nonenzymatic antioxidant defense systems dominated by divalent manganese complexes. Given that oxidative stress caused by the accumulation of reactive oxygen species is associated with aging and cancer, a comprehensive outlook on D. radiodurans strategies of combating oxidative stress may open new avenues for antiaging and anticancer treatments. The study of the antioxidation protection in D. radiodurans is therefore of considerable potential interest for medicine and public health.

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Section: Recombinational Processes In D Radiodurans Dna Repairmentioning

confidence: 99%

Oxidative Stress Resistance inDeinococcus radiodurans

Slade

Radman

2011

Microbiol Mol Biol Rev

646

639

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“…Interestingly, the RecQ enzyme from Rhodobacter sphaeroides contains two HRDC domains, while other RecQ helicases from Deinococcus radiodurans, Neisseria meningitidis, and Neisseria gonorrhea are characterized by possessing three HRDC repeats. These multiple HRDC domains regulate the enzymatic activity of Deinococcus radiodurans RecQ and differentially affect the ability of the enzyme to bind and unwind DNA (Killoran and Keck, 2006) (see Fig. 3).…”

Section: The Helicase-and-rnased-like-c-terminal Domainmentioning

confidence: 99%

RecQ helicases: Multiple structures for multiple functions?

Vindigni

Hickson

2009

HFSP Journal

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“…1). Only one other organism, Deinococcus radiodurans, has been reported to possess this unusual RecQ triple-HRDC domain structure (20), while most RecQs contain one HRDC domain and a few RecQ orthologs have no HRDC repeats ( Fig. 1).…”

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confidence: 99%

Neisseria gonorrhoeae RecQ Helicase HRDC Domains Are Essential for Efficient Binding and Unwinding of the pilE Guanine Quartet Structure Required for Pilin Antigenic Variation

et al. 2013

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The strict human pathogen Neisseria gonorrhoeae utilizes homologous recombination to antigenically vary the pilus, thus evading the host immune response. High-frequency gene conversion reactions between many silent pilin loci and the expressed pilin locus (pilE) allow for numerous pilus variants per strain to be produced from a single strain. For pilin antigenic variation (Av) to occur, a guanine quartet (G4) structure must form upstream of pilE. The RecQ helicase is one of several recombination or repair enzymes required for efficient levels of pilin Av, and RecQ family members have been shown to bind to and unwind G4 structures. Additionally, the vast majority of RecQ helicase family members encode one "helicase and RNase D C-terminal" (HRDC) domain, whereas the N. gonorrhoeae RecQ helicase gene encodes three HRDC domains, which are critical for pilin Av. Here, we confirm that deletion of RecQ HRDC domains 2 and 3 causes a decrease in the frequency of pilin Av comparable to that obtained with a functional knockout. We demonstrate that the N. gonorrhoeae RecQ helicase can bind and unwind the pilE G4 structure. Deletion of the RecQ HRDC domains 2 and 3 resulted in a decrease in G4 structure binding and unwinding. These data suggest that the decrease in pilin Av observed in the RecQ HRDC domain 2 and 3 deletion mutant is a result of the enzyme's inability to efficiently bind and unwind the pilE G4 structure.

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Three HRDC Domains Differentially Modulate Deinococcus radiodurans RecQ DNA Helicase Biochemical Activity

Cited by 32 publications

References 49 publications

Oxidative Stress Resistance inDeinococcus radiodurans

Oxidative Stress Resistance inDeinococcus radiodurans

RecQ helicases: Multiple structures for multiple functions?

Neisseria gonorrhoeae RecQ Helicase HRDC Domains Are Essential for Efficient Binding and Unwinding of the pilE Guanine Quartet Structure Required for Pilin Antigenic Variation

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