Structure of the Prx6-subfamily 1-Cys peroxiredoxin from Sulfolobus islandicus.
Stroobants, S., Van Molle, I., Saidi, Q., Jonckheere, K., Maes, D., Peeters, E.(2019) Acta Crystallogr F Struct Biol Commun 75: 428-434
- PubMed: 31204689 
- DOI: https://doi.org/10.1107/S2053230X19006472
- Primary Citation of Related Structures:  
6Q5V - PubMed Abstract: 
Aerobic thermoacidophilic archaea belonging to the genus Sulfolobus harbor peroxiredoxins, thiol-dependent peroxidases that assist in protecting the cells from oxidative damage. Here, the crystal structure of the 1-Cys peroxiredoxin from Sulfolobus islandicus, named 1-Cys SiPrx, is presented. A 2.75 Å resolution data set was collected from a crystal belonging to space group P2 1 2 1 2 1 , with unit-cell parameters a = 86.8, b = 159.1, c = 189.3 Å, α = β = γ = 90°. The structure was solved by molecular replacement using the homologous Aeropyrum pernix peroxiredoxin (ApPrx) structure as a search model. In the crystal structure, 1-Cys SiPrx assembles into a ring-shaped decamer composed of five homodimers. This quaternary structure corresponds to the oligomeric state of the protein in solution, as observed by size-exclusion chromatography. 1-Cys SiPrx harbors only a single cysteine, which is the peroxidatic cysteine, and lacks both of the cysteines that are highly conserved in the C-terminal arm domain in other archaeal Prx6-subfamily proteins such as ApPrx and that are involved in the association of dimers into higher-molecular-weight decamers and dodecamers. It is thus concluded that the Sulfolobus Prx6-subfamily protein undergoes decamerization independently of arm-domain cysteines.
Organizational Affiliation: 
Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.