Phylogenetic and bioinformatics analysis of chitinase encoding cDNA from Fenneropenaeus mergueinsis

Chitinases are essential enzymes in crustaceans that play an important role in the molting cycle and digestion of chitin. Based on the present study, the chitinase encoding cDNA of Penaeus mergueinsis with a length of 1440 bp containing 467 amino acids was sequenced by PCR and then its phylogenetic and bioinformatics analysis was performed. The new sequence was registered in the gene bank with the accessition number MT250539 and the molecular weight of the protein resulting from this sequence was predicted to be 51.84 KDa and the theoretical isoelectric point of 4.79. Comparison of amino acid sequences among penaeid chitinases showed the highest identification (about 97 to 92%) with P. mondon chi-3, F. chinensis, P. vannamei and P. japonicus chi-3, respectively. Phylogenetic studies showed that chitinase in the present study belongs to group 3 chitinases. Revealed protein pattern analyzes showed that chitinase from P. mergueinsis contained the catalytic domain Glyco-18 at position 2-347, a chitin-binding site of pritrophin A at position 403-456, a disulfide bridge formed by two cysteines at position 436-421 is a chitin-binding domain type 2, active site (117FDGLDMDWE125), a proline / threonine-rich region at positions 376-412, and a putative N-glycosylation site at position 427-424 (NTSG). The present study shows that the P. mergueinsis sequence contains active chitinase motifs similar to previously sequenced chitinases, and in the case of cloning, expression and purification probably has functional and structural features similar to the enzymes of the above species.