title: Structural implications of the C-terminal tail in the catalytic and stability properties of manganese peroxidases from ligninolytic fungi.
abstract: The genome of Ceriporiopsis subvermispora includes 13 manganese peroxidase (MnP) genes representative of the three subfamilies described in ligninolytic fungi, which share an Mn(2+)-oxidation site and have varying lengths of the C-terminal tail. Short, long and extralong MnPs were heterologously expressed and biochemically characterized, and the first structure of an extralong MnP was solved. Its C-terminal tail surrounds the haem-propionate access channel, contributing to Mn(2+) oxidation by the internal propionate, but prevents the oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS), which is only oxidized by short MnPs and by shortened-tail variants from site-directed mutagenesis. The tail, which is anchored by numerous contacts, not only affects the catalytic properties of long/extralong MnPs but is also associated with their high acidic stability. Cd(2+) binds at the Mn(2+)-oxidation site and competitively inhibits oxidation of both Mn(2+) and ABTS. Moreover, mutations blocking the haem-propionate channel prevent substrate oxidation. This agrees with molecular simulations that position ABTS at an electron-transfer distance from the haem propionates of an in silico shortened-tail form, while it cannot reach this position in the extralong MnP crystal structure. Only small differences exist between the long and the extralong MnPs, which do not justify their classification as two different subfamilies, but they significantly differ from the short MnPs, with the presence/absence of the C-terminal tail extension being implicated in these differences.
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Fernández-Fueyo
authors.affiliation: Joint BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, Jordi Girona 29, 08034 Barcelona, Spain.
authors.forename: Sandra
authors.initials: S
authors.lastname: Acebes
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Ruiz-Dueñas
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Martínez
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Romero
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Medrano
authors.affiliation: Joint BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, Jordi Girona 29, 08034 Barcelona, Spain.
authors.forename: Victor
authors.initials: V
authors.lastname: Guallar
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Angel T
authors.initials: AT
authors.lastname: Martínez
mesh_terms: D052160:Benzothiazoles / Q000378:metabolism; D002413:Cations, Divalent / Q000378:metabolism; D055453:Coriolaceae / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D004795:Enzyme Stability; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D013451:Sulfonic Acids / Q000378:metabolism
chemical_list: D052160:Benzothiazoles; D002413:Cations, Divalent; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D010544:Peroxidases; C051129:manganese peroxidase
keywords: C-terminal tail; Ceriporiopsis subvermispora; manganese peroxidase