Structure of the Prx6‐subfamily 1‐Cys peroxiredoxin from Sulfolobus islandicus

• Published in: Acta crystallographica. Section F, Structural biology communications Structural biology communications, 2019-06, Vol.75 (6), p.428-434
• Main Authors: Stroobants, Sander, Van Molle, Inge, Saidi, Queen, Jonckheere, Karl, Maes, Dominique, Peeters, Eveline
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Archaea; chaperones; Crystal structure; Crystallography, X-Ray; Cysteine; Cysteine - chemistry; Cysteine - metabolism; Dimers; Homology; Models, Molecular; Molecular structure; Peroxiredoxin; peroxiredoxins; Peroxiredoxins - chemistry; Peroxiredoxins - metabolism; Protein Conformation; Protein Multimerization; Protein structure; Proteins; Prx6; Quaternary structure; Research Communications; Sequence Homology; Structural damage; Sulfolobus; Sulfolobus - metabolism; Sulfolobus islandicus
• ISSN: 2053-230X; 2053-230X
• DOI: 10.1107/S2053230X19006472

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 P212121, 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. The crystal structure of the 1‐Cys peroxiredoxin from S. islandicus is presented; it assembles into a ring‐shaped decamer composed of five homodimers. It is concluded that this Prx6‐like protein undergoes decamerization independently of arm‐domain cysteines.