title: DyP, a unique dye-decolorizing peroxidase, represents a novel heme peroxidase family: ASP171 replaces the distal histidine of classical peroxidases.
abstract: DyP, a unique dye-decolorizing enzyme from the fungus Thanatephorus cucumeris Dec 1, has been classified as a peroxidase but lacks homology to almost all other known plant peroxidases. The primary structure of DyP shows moderate sequence homology to only two known proteins: the peroxide-dependent phenol oxidase, TAP, and the hypothetical peroxidase, cpop21. Here, we show the first crystal structure of DyP and reveal that this protein has a unique tertiary structure with a distal heme region that differs from that of most other peroxidases. DyP lacks an important histidine residue known to assist in the formation of a Fe4+ oxoferryl center and a porphyrin-based cation radical intermediate (compound I) during the action of ubiquitous peroxidases. Instead, our tertiary structural and spectrophotometric analyses of DyP suggest that an aspartic acid and an arginine are involved in the formation of compound I. Sequence analysis reveals that the important aspartic acid and arginine mentioned above and histidine of the heme ligand are conserved among DyP, TAP, and cpop21, and structural and phylogenetic analyses confirmed that these three enzymes do not belong to any other families of peroxidase. These findings, which strongly suggest that DyP is a representative heme peroxidase from a novel family, should facilitate the identification of additional new family members and accelerate the classification of this novel peroxidase family.
authors.affiliation: R1-29 Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan. ysugano@res.titech.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sugano
authors.forename: Riichi
authors.initials: R
authors.lastname: Muramatsu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ichiyanagi
authors.forename: Takao
authors.initials: T
authors.lastname: Sato
authors.forename: Makoto
authors.initials: M
authors.lastname: Shoda
mesh_terms: D001487:Basidiomycota / Q000201:enzymology* / Q000235:genetics; D001665:Binding Sites / Q000502:physiology; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics; D006418:Heme / Q000737:chemistry* / Q000235:genetics; D006420:Hemeproteins / Q000737:chemistry* / Q000235:genetics; D007501:Iron / Q000737:chemistry*; D014442:Monophenol Monooxygenase / Q000737:chemistry / Q000235:genetics; D009195:Peroxidase / Q000737:chemistry* / Q000235:genetics; D010802:Phylogeny; D020836:Protein Structure, Quaternary; D040681:Structural Homology, Protein
chemical_list: D005656:Fungal Proteins; D006420:Hemeproteins; D006418:Heme; D007501:Iron; D009195:Peroxidase; D014442:Monophenol Monooxygenase