title: Mapping the Long-Range Electron Transfer Route in Ligninolytic Peroxidases.
abstract: Combining a computational analysis with site-directed mutagenesis, we have studied the long-range electron transfer pathway in versatile and lignin peroxidases, two enzymes of biotechnological interest that play a key role for fungal degradation of the bulky lignin molecule in plant biomass. The in silico study established two possible electron transfer routes starting at the surface tryptophan residue previously identified as responsible for oxidation of the bulky lignin polymer. Moreover, in both enzymes, a second buried tryptophan residue appears as a top electron transfer carrier, indicating the prevalence of one pathway. Site-directed mutagenesis of versatile peroxidase (from Pleurotus eryngii) allowed us to corroborate the computational analysis and the role played by the buried tryptophan (Trp244) and a neighbor phenylalanine residue (Phe198), together with the surface tryptophan, in the electron transfer. These three aromatic residues are highly conserved in all the sequences analyzed (up to a total of 169). The importance of the surface (Trp171) and buried (Trp251) tryptophan residues in lignin peroxidase has been also confirmed by directed mutagenesis of the Phanerochaete chrysosporium enzyme. Overall, the combined procedure identifies analogous electron transfer pathways in the long-range oxidation mechanism for both ligninolytic peroxidases, constituting a good example of how computational analysis avoids making extensive trial-error mutagenic experiments.
authors.affiliation: Barcelona Supercomputing Center, Joint BSC-CRG-IRB Research Program in Computational Biology , Jordi Girona 29, E-08034 Barcelona, Spain.
authors.forename: Sandra
authors.initials: S
authors.lastname: Acebes
authors.affiliation: Centro de Investigaciones Biológicas, CSIC , Ramiro de Maeztu 9, E-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, E-28040 Madrid, Spain.
authors.forename: Mario
authors.initials: M
authors.lastname: Toubes
authors.affiliation: Centro de Investigaciones Biológicas, CSIC , Ramiro de Maeztu 9, E-28040 Madrid, Spain.
authors.forename: Veronica
authors.initials: V
authors.lastname: Sáez-Jiménez
authors.affiliation: Centro de Investigaciones Biológicas, CSIC , Ramiro de Maeztu 9, E-28040 Madrid, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Pérez-Boada
authors.affiliation: Barcelona Supercomputing Center, Joint BSC-CRG-IRB Research Program in Computational Biology , Jordi Girona 29, E-08034 Barcelona, Spain.|Anaxomics Biotech , Balmes 89, 08008 Barcelona, Spain.
authors.forename: M Fátima
authors.initials: MF
authors.lastname: Lucas
authors.affiliation: Centro de Investigaciones Biológicas, CSIC , Ramiro de Maeztu 9, E-28040 Madrid, Spain.
authors.forename: Angel T
authors.identifier: 0000-0002-1584-2863
authors.initials: AT
authors.lastname: Martínez
authors.affiliation: Barcelona Supercomputing Center, Joint BSC-CRG-IRB Research Program in Computational Biology , Jordi Girona 29, E-08034 Barcelona, Spain.|ICREA , Passeig Lluís Companys 23, E-08010 Barcelona, Spain.
authors.forename: Victor
authors.identifier: 0000-0002-4580-1114
authors.initials: V
authors.lastname: Guallar
mesh_terms: D000595:Amino Acid Sequence; D004579:Electron Transport; D008031:Lignin / Q000378:metabolism; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020076:Pleurotus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D013379:Substrate Specificity
chemical_list: D008031:Lignin; D010544:Peroxidases; C042858:lignin peroxidase