title: Cloning and characterization of Arenicola marina peroxiredoxin 6, an annelid two-cysteine peroxiredoxin highly homologous to mammalian one-cysteine peroxiredoxins.
abstract: Peroxiredoxins (PRDXs) are a superfamily of thiol-dependent peroxidases found in all phyla. PRDXs are mechanistically divided into three subfamilies, namely typical 2-Cys, atypical 2-Cys, and 1-Cys PRDXs. To reduce peroxides, the N-terminal peroxidatic Cys of PRDXs is first oxidized into sulfenic acid. This intermediate is reduced by forming a disulfide bond either with a resolving Cys of another monomeric entity (typical 2-Cys) or of the same molecule (atypical 2-Cys). In 1-Cys PRDXs, the resolving Cys is missing and the sulfenic acid of the peroxidatic Cys is reduced by a heterologous thiol-containing reductant. In search of a homolog of human 1-Cys PRDX6 in Arenicola marina, an annelid worm living in intertidal sediments, we have cloned and characterized a PRDX exhibiting high sequence homology with its mammalian counterpart. However, A. marina PRDX6 possesses five Cys among which two Cys function as peroxidatic and resolving Cys of typical 2-Cys PRDXs. Thus, A. marina PRDX6 belongs to a transient group exhibiting sequence homologies with mammalian 1-Cys PRDX6 but must be mechanistically classified into typical 2-Cys PRDXs. Moreover, PRDX6 is highly expressed in tissues directly exposed to the external environment, suggesting that this PRDX may be of particular importance for protection against exogenous oxidative attacks.
authors.affiliation: Laboratoire de Biologie Cellulaire, Institut des Sciences de la Vie, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors.forename: Eléonore
authors.initials: E
authors.lastname: Loumaye
authors.forename: Ann C
authors.initials: AC
authors.lastname: Andersen
authors.forename: André
authors.initials: A
authors.lastname: Clippe
authors.forename: Hervé
authors.initials: H
authors.lastname: Degand
authors.forename: Marlène
authors.initials: M
authors.lastname: Dubuisson
authors.forename: Franck
authors.initials: F
authors.lastname: Zal
authors.forename: Pierre
authors.initials: P
authors.lastname: Morsomme
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Rees
authors.forename: Bernard
authors.initials: B
authors.lastname: Knoops
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000845:Annelida / Q000201:enzymology*; D001483:Base Sequence; D002384:Catalysis; D003001:Cloning, Molecular; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D054465:Peroxiredoxin VI / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D054465:Peroxiredoxin VI; D003545:Cysteine