Genome mining of Fusariumreveals structural and functional diversity of pectin lyases: a bioinformatics approach

Pectin lyase (PNL) is an important enzyme of the pectinases group which degrades pectin polymer to 4,5-unsaturated oligogalacturonides by a unique β-elimination mechanism and is used in several industries. The existence of multigene families of pectin lyases has been investigated by mining microbial genomes. In the present study, 52 pectin lyase genes were predicted from sequenced six species of Fusarium,namely F. fujikuroi,F. graminearum,F. proliferatum,F. oxysporum,F. verticillioidesand F. virguliforme.These sequences were in silicocharacterized for several physico-chemical, structural and functional attributes. The translated PNL proteins showed variability with 344–1142 amino acid residues, 35.44–127.41 kDa molecular weight, and pI ranging from 4.63 to 9.28. The aliphatic index ranged from 75.33 to 84.75. Multiple sequence alignment analysis showed several conserved amino acid residues and five distinct groups marked as I, II, III, IV, and V were observed in the phylogenetic tree. The Three-dimensional Structure of five of these PNLs, each representing a distinct group of phylogenetic trees was predicted using I-TASSER Server and validated. The pectin lyase proteins of Fusariumspecies revealed close similarity with pectin lyase of Aspergillus nigerPelA(1IDJ) and PelB(1QCX). Diversity in the structural motifs was observed among Fusariumspecies with 2 β-sheets, 1 β-hairpin, 7–12 β bulges, 18–25 strands, 6 -11 helices, 1 helix-helix interaction, 32–49 β turns, 2–6 γ turns and 2- 3 disulfide bonds. The unique Pec_lyase domain was uniformly observed among all PNL proteins confirming its identity. The genome-wide mining of Fusariumspecies was attempted to provide the diversity of PNLgenes, which could be explored for diverse applications after performing cloning and expression studies.