Structural and Phylogenetic Analysis of Laccases from Trichoderma: A Bioinformatic Approach

Abstract

The genus Trichoderma includes species of great biotechnological value, both for their mycoparasitic activities and for their ability to produce extracellular hydrolytic enzymes. Although activity of extracellular laccase has previously been reported in Trichoderma spp., the possible number of isoenzymes is still unknown, as are the structural and functional characteristics of both the genes and the putative proteins. In this study, the system of laccases sensu stricto in the Trichoderma species, the genomes of which are publicly available, were analyzed using bioinformatic tools. The intron/exon structure of the genes and the identification of specific motifs in the sequence of amino acids of the proteins generated in silico allow for clear differentiation between extracellular and intracellular enzymes. Phylogenetic analysis suggests that the common ancestor of the genus possessed a functional gene for each one of these enzymes, which is a characteristic preserved in T. atroviride and T. virens. This analysis also reveals that T. harzianum and T. reesei only retained the intracellular activity, whereas T. asperellum added an extracellular isoenzyme acquired through horizontal gene transfer during the mycoparasitic process. The evolutionary analysis shows that in general, extracellular laccases are subjected to purifying selection, and intracellular laccases show neutral evolution. The data provided by the present study will enable the generation of experimental approximations to better understand the physiological role of laccases in the genus Trichoderma and to increase their biotechnological potential.

Degradation of polycyclic aromatic hydrocarbons in soil by a tolerant strain of Trichoderma asperellum

“…In contrast, aromatic-ringhydroxylating dioxygenases are more commonly found in bacteria and greatly contribute to the initial ring cleavage of aromatic compounds, including LMW PAHs (Hadibarata and Tachibana 2010). Probable mechanisms for PAH degradation in T. asperellum could include the production of laccases (Cazares-Garcia et al 2013), peroxidases (Cristica et al 2010), and dioxygenases (Hadibarata et al 2007) among others. We observed that the presence of PAHs in liquid cultures led to a significant increase in the activity of catechol 1,2 and 2,3 dioxygenases during the initial 4 days of incubation, reaching a maximum production at day 6 and a subsequent decrease from day 8.…”

“…It is likely that T. asperellum laccases are involved in the oxidation of aromatic rings and play a crucial role in the degradation of PAHs by T. asperellum, as they are strongly linked to aromatic hydrocarbon degradation in other fungi (Baldrian 2006;Haritash and Kaushik 2009). Three different T. asperellum laccase genes have been identified in silico (Cazares-Garcia et al 2013), two of them being extracellular enzymes with probable PAH-oxidizing capacity. On the other hand, there is no evidence of classic fungal peroxidases such as MnP and LiP in T. asperellum genome, nor in the secretome of this fungus grown in sugarcane bagasse (Marx et al 2013).…”

“…However, there are no reports involving T. asperellum as a hydrocarbon or PAH-degrading organism. The use of T. asperellum as bioremediation agent on PAHpolluted soils may present additional advantages over the use of other soil microorganisms, such as its high growth rate, wide range of substrates, growth-promoting effects on plants, and the production of oxidizing hydrolytic enzymes including laccases, peroxidises, and dioxygenases (Cazares-Garcia et al 2013;Hadibarata et al 2007). Thus, the aim of this work was to evaluate the degradation capability of a strain of T. asperellum tolerant to LMW and HMW-PAHs in solid culture, for the bioremediation of PAH-polluted soils.…”

Lessons from characterization and treatment of the autoinflammatory syndromes

“…LACC1 is a multicopper oxidoreductase that catalyzes the oxidation of a variety of aromatic substrates, such as phenolic and non-phenolic compounds, with the concomitant reduction of molecular oxygen to water [46]. A study to identify the biological mechanism(s) affected by the C284R and I254V coding variations in LACC1 [47] found that the protein, renamed as ‘FAMIN’ (‘fatty acid metabolism–immunity nexus’) functions as a ‘rheostat’ for the synthesis of endogenous fatty acids (FA) and their mitochondrial oxidation and thereby controlled glycolytic activity and overall ATP regeneration.…”

Exploring laccase genes from plant pathogen genomes: a bioinformatic approach

“…Reports have shown that laccases exist as a gene family in bacteria (Ausec et al, 2011), fungi (Hoegger et al, 2004;Courty et al, 2009;Cázares-Garcia et al, 2013) and oomycetes (Feng and Li, 2012). Plant pathogenic fungi also produce many kinds of laccases.…”