Cloning, Expression, and Characterization of Prophenoloxidases from Asian Corn Borer, Ostrinia furnacalis (Gunée)

Figure 3

Multiple sequence alignment of conserved regions of insect PPOs. Amino acid sequences of PPOs from O. furnacalis PPO1a (OfPPO1a, KX452359), PPO1b (OfPPO1b, KX437622), PPO2 (OfPPO2, ABC59699), PPO3 (OfPPO3, KX437621), B. mori PPO1 (BmPPO1, AAG09304), PPO2 (BmPPO2, D49371), M. sexta PPO1 (MsPPO1, AF003253), PPO2 (MsPPO2, AAC37243), and H. diomphalia PPO1 (HdPPO1, AB079665) were aligned using the Clustal W. Alignments of potential cleavage sites (a), two independent copper binding sites (b and c), and two C-terminal conserved motifs (d) are shown. Numbers on both ends of each peptide represented amino acid residue numbers of the respective proteins. Amino acid residues shared by four or more proteins are shown by white letters on black background, while conservative amino acid substitutions are on grey background. Asterisks on the bottom of the alignment denoted amino acids shared by all proteins while small dots indicate conservatively substituted amino acids. The arrows in (a) indicate the potential proteolytic cleavage sites for PPO activation. Three large dots in (b) and (c) indicate the histidine residues coordinated with the copper atoms.

(a)

(b)

(c)

(d)