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Structure of the Prx6‐subfamily 1‐Cys peroxiredoxin from Sulfolobus islandicus
Author(s) -
Stroobants Sander,
Van Molle Inge,
Saidi Queen,
Jonckheere Karl,
Maes Dominique,
Peeters Eveline
Publication year - 2019
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 37
ISSN - 2053-230X
DOI - 10.1107/s2053230x19006472
Subject(s) - sulfolobus , subfamily , biology , peroxiredoxin , cysteine , archaea , molecular replacement , sulfolobus solfataricus , biochemistry , protein quaternary structure , protein structure , stereochemistry , chemistry , enzyme , protein subunit , peroxidase , gene
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 P 2 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.