Essential component of the organic matrix for normal growth of the nacreous layer. The complex contributes to the initiation of aragonite crystallization as well as subsequenct stacking of aragonite tablets in the nacreous layer. Pif80 binds to both aragonite and calcite crystals, with a higher specificity to aragonite crystals. Pif97 contains a chitin-binding domain that allows for attachment of the entire complex to the chitin-containing organic framework. Heterooligomer; disulfide-linked. Pif97, Pif80, N16 and other proteins form a complex. Component of conchiolin, the organic matrix of nacre. Expressed at extremely high levels in the dorsal region of the mantle, which region may be responsible for the nacreous layer formation, but only in trace amounts at the mantle edge, which region may be responsible for the prismatic layer formation. Pif80 and Pif97 are rich in Asp. This amino-acid appears to be common to biomineral-forming organisms. String of intrusion - Issue 112 of December 2009