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A novel starch-binding laccase from the wheat pathogen Zymoseptoria tritici highlights the functional diversity of ascomycete laccases

Haddad Momeni, Majid; Bollella, Paolo; Ortiz, Roberto LU ; Thormann, Esben; Gorton, Lo LU and Abou Hachem, Maher LU (2019) In BMC Biotechnology 19.
Abstract

Background: Laccases are multicopper oxidases, which are assigned into auxiliary activity family 1 (AA1) in the CAZy database. These enzymes, catalyzing the oxidation of phenolic and nonphenolic substrates coupled to reduction of O2 to H2O, are increasingly attractive as eco-friendly oxidation biocatalysts. Basidiomycota laccases are well characterized due to their potential in de-lignification of lignocellulose. By contrast, insight into the biochemical diversity of Ascomycota counterparts from saprophytes and plant pathogens is scarce. Results: Here, we report the properties of the laccase from the major wheat pathogen Zymoseptoria tritici (ZtrLac1A), distinguished from common plant fungal pathogens by an... (More)

Background: Laccases are multicopper oxidases, which are assigned into auxiliary activity family 1 (AA1) in the CAZy database. These enzymes, catalyzing the oxidation of phenolic and nonphenolic substrates coupled to reduction of O2 to H2O, are increasingly attractive as eco-friendly oxidation biocatalysts. Basidiomycota laccases are well characterized due to their potential in de-lignification of lignocellulose. By contrast, insight into the biochemical diversity of Ascomycota counterparts from saprophytes and plant pathogens is scarce. Results: Here, we report the properties of the laccase from the major wheat pathogen Zymoseptoria tritici (ZtrLac1A), distinguished from common plant fungal pathogens by an apoplastic infection strategy. We demonstrate that ZtrLac1A is appended to a functional starch-binding module and displays an activity signature disfavoring relatively apolar phenolic redox mediators as compared to the related biochemically characterized laccases. By contrast, the redox potential of ZtrLac1A (370 mV vs. SHE) is similar to ascomycetes counterparts. The atypical specificity is consistent with distinctive sequence substitutions and insertions in loops flanking the T1 site and the enzyme C-terminus compared to characterized laccases. Conclusions: ZtrLac1A is the first reported modular laccase appended to a functional starch-specific carbohydrate binding module of family 20 (CBM20). The distinct specificity profile of ZtrLac1A correlates to structural differences in the active site region compared to previously described ascomycetes homologues. These differences are also highlighted by the clustering of the sequence of ZtrLac1A in a distinct clade populated predominantly by plant pathogens in the phylogenetic tree of AA1 laccases. The possible role of these laccases in vivo merits further investigations. These findings expand our toolbox of laccases for green oxidation and highlight the binding functionality of CBM-appended laccases as versatile immobilization tags.

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organization
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type
Contribution to journal
publication status
published
subject
keywords
Carbohydrate binding module family 20 (CBM20), Cyclic voltammograms, Laccase, Oxidoreductase, Pathogen, Plant, Starch, Zymoseptoria tritici
in
BMC Biotechnology
volume
19
publisher
BioMed Central
external identifiers
  • scopus:85070893012
ISSN
1472-6750
DOI
10.1186/s12896-019-0552-4
language
English
LU publication?
yes
id
68fa481f-5609-4a23-81d2-90ab035e19e0
date added to LUP
2019-09-24 14:31:29
date last changed
2019-09-26 04:44:39
@article{68fa481f-5609-4a23-81d2-90ab035e19e0,
  abstract     = {<p>Background: Laccases are multicopper oxidases, which are assigned into auxiliary activity family 1 (AA1) in the CAZy database. These enzymes, catalyzing the oxidation of phenolic and nonphenolic substrates coupled to reduction of O<sub>2</sub> to H<sub>2</sub>O, are increasingly attractive as eco-friendly oxidation biocatalysts. Basidiomycota laccases are well characterized due to their potential in de-lignification of lignocellulose. By contrast, insight into the biochemical diversity of Ascomycota counterparts from saprophytes and plant pathogens is scarce. Results: Here, we report the properties of the laccase from the major wheat pathogen Zymoseptoria tritici (ZtrLac1A), distinguished from common plant fungal pathogens by an apoplastic infection strategy. We demonstrate that ZtrLac1A is appended to a functional starch-binding module and displays an activity signature disfavoring relatively apolar phenolic redox mediators as compared to the related biochemically characterized laccases. By contrast, the redox potential of ZtrLac1A (370 mV vs. SHE) is similar to ascomycetes counterparts. The atypical specificity is consistent with distinctive sequence substitutions and insertions in loops flanking the T1 site and the enzyme C-terminus compared to characterized laccases. Conclusions: ZtrLac1A is the first reported modular laccase appended to a functional starch-specific carbohydrate binding module of family 20 (CBM20). The distinct specificity profile of ZtrLac1A correlates to structural differences in the active site region compared to previously described ascomycetes homologues. These differences are also highlighted by the clustering of the sequence of ZtrLac1A in a distinct clade populated predominantly by plant pathogens in the phylogenetic tree of AA1 laccases. The possible role of these laccases in vivo merits further investigations. These findings expand our toolbox of laccases for green oxidation and highlight the binding functionality of CBM-appended laccases as versatile immobilization tags.</p>},
  articleno    = {61},
  author       = {Haddad Momeni, Majid and Bollella, Paolo and Ortiz, Roberto and Thormann, Esben and Gorton, Lo and Abou Hachem, Maher},
  issn         = {1472-6750},
  keyword      = {Carbohydrate binding module family 20 (CBM20),Cyclic voltammograms,Laccase,Oxidoreductase,Pathogen,Plant,Starch,Zymoseptoria tritici},
  language     = {eng},
  month        = {08},
  publisher    = {BioMed Central},
  series       = {BMC Biotechnology},
  title        = {A novel starch-binding laccase from the wheat pathogen Zymoseptoria tritici highlights the functional diversity of ascomycete laccases},
  url          = {http://dx.doi.org/10.1186/s12896-019-0552-4},
  volume       = {19},
  year         = {2019},
}