A total of 28 pectate lyase (PL) sequences representing different species of Aspergillus namely A. flavus, A. niger, A. nidulans, A. fumigatus, A. oryzae, A. clavatus and A. terreus were retrieved from NCBI databases and in-silico characterized for structural diversity. The translated amino acids sequences of these PL genes of Aspergillus were also accessed for various physio-chemical features like molecular weight, theoretical PI, amino acid composition, atomic composition, extinction coefficient, estimated half-life, instability index, aliphatic index and grand average of hydropathicity (GRAVY).These sequences exhibit multiple introns and revealed a conserved pectate lyases domain irrespective of Aspergillus species, suggesting its possible role in structural and catalytic attributes of PLs. Homology modeling was performed with Swiss-model workspace at automated mode with selected template to predict the 3D structures of PL proteins. The stability of the 3D models were confirmed by PROCHECK showing more than 95% of the amino acid residues in favored and allowed region of Ramachandran plot and also by favorable QMEAN-Z score. The phylogenetic tree constructed revealed four distinct groups which were further subjected for functional divergence studies. The coefficient of functional divergence (Ɵ) among different groups was found to be less than 1 indicating significant site–specific selective constraints. The bioinformatics study of pectate lyases of different species of Aspergillus gives an insight to the structural variability which further needs to be analyzed for functional attributes.
Manish Kumar, Sangeeta Yadav, Jeya Nasim, Dinesh Yadav. Computational assessment of predicted three dimensional structures of Pectate lyases from different species of Aspergillus using homology modeling. European Journal of Biotechnology and Bioscience, Volume 2, Issue 6, 2014, Pages 59-71