Pif-177 and Pmarg -Pif protein sequence comparison. (A). Schematic representation of Pif-177 and Pmarg- Pif protein structures. Pif-97 consists of 525 amino acids (from a.a. 23 to 547) and Pmarg- Pif-97 consists of 536 amino acids (from a.a. 23 to 558). Pif-80 consists of 460 amino acids (from a.a. 548 to 1007) and Pmarg- Pif-80 consists of 456 amino acids (from a.a. 559 to 1014). Purple box is the signal peptide. Blue VWA box is von-Willebrand type A domain. Green CHIT box is a chitin-binding domain. Yellow box is aragonite-binding protein. The four-amino-acid motifs (DD-R/K-R/K) are indicated by asterisks, and arrows indicate motifs at conserved positions between the two sequences. Red box, in the aragonite-binding protein, indicates the cluster of acidic amino acid residues. (LVKEIERRKSDDK-K/I-S-F/L-DD) consensus motif repeated three times in Pmarg- Pif is boxed under aragonite-binding protein. (B) Alignments of the Pif-177 and Pmarg- Pif amino acid sequences of the von Willebrand type A domain and chitin-binding domain. Residues shaded in black are identical residues, and grey positions indicate conserved residues. Sequences are preceded and followed by numbers indicating the domain position in the entire sequence. Percentage of identity are indicated.