ID   MA20_PINMA              Reviewed;          21 AA.
AC   P0CAY9;
DT   28-JUL-2009, integrated into UniProtKB/Swiss-Prot.
DT   28-JUL-2009, sequence version 1.
DT   02-JUN-2021, entry version 14.
DE   RecName: Full=Conchiolin protein p20;
DE   Flags: Fragment;
OS   Pinctada maxima (Silver-lipped pearl oyster) (White-lipped pearl oyster).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Bivalvia;
OC   Autobranchia; Pteriomorphia; Pterioida; Pterioidea; Pteriidae; Pinctada.
OX   NCBI_TaxID=104660;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, AND SUBUNIT.
RC   TISSUE=Nacre;
RX   PubMed=11250534; DOI=10.1016/s1096-4959(00)00337-7;
RA   Bedouet L., Schuller M.J., Marin F., Milet C., Lopez E., Giraud M.;
RT   "Soluble proteins of the nacre of the giant oyster Pinctada maxima and of
RT   the abalone Haliotis tuberculata: extraction and partial analysis of nacre
RT   proteins.";
RL   Comp. Biochem. Physiol. 128B:389-400(2001).
RN   [2]
RP   PHARMACEUTICAL.
RX   PubMed=9183443; DOI=10.1016/s0764-4469(97)86933-8;
RA   Atlan G., Balmain N., Berland S., Vidal B., Lopez E.;
RT   "Reconstruction of human maxillary defects with nacre powder: histological
RT   evidence for bone regeneration.";
RL   C. R. Acad. Sci. III, Sci. Vie 320:253-258(1997).
CC   -!- FUNCTION: May be specifically involved in the formation of the nacreous
CC       layer. {ECO:0000269|PubMed:11250534}.
CC   -!- SUBUNIT: Homooligomer; disulfide-linked. May also be disulfide-linked
CC       to insoluble organic matrix. {ECO:0000269|PubMed:11250534}.
CC   -!- SUBCELLULAR LOCATION: Secreted, extracellular space, extracellular
CC       matrix.
CC   -!- TISSUE SPECIFICITY: Component of conchiolin, the organic matrix of
CC       nacre. Is dispersed in calcium carbonate and also linked by disulfide
CC       bonds to the organic core of nacre.
CC   -!- PTM: According to PubMed:11250534, amino acids 4 and 11 may be sulfated
CC       or phosphorylated. By similarity with the N14 matrix protein, amino-
CC       acid 4 may be a cysteine involved in a disulfide bond.
CC   -!- PHARMACEUTICAL: P.maxima nacre is used in implants to induce in vivo
CC       osteogenesis.
CC   -!- SIMILARITY: Belongs to the N16 matrix protein family. {ECO:0000305}.
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DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Extracellular matrix;
KW   Pharmaceutical; Secreted.
FT   CHAIN           1..>21
FT                   /note="Conchiolin protein p20"
FT                   /id="PRO_0000379785"
FT   REGION          1..21
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   VARIANT         5
FT                   /note="S -> D"
FT   VARIANT         12
FT                   /note="G -> L"
FT   VARIANT         13
FT                   /note="P -> L"
FT   VARIANT         17
FT                   /note="I -> E"
FT   VARIANT         18
FT                   /note="D -> EAR"
FT   NON_TER         21
SQ   SEQUENCE   21 AA;  2728 MW;  9A8096EBA772698D CRC64;
     YQRXSRYYYY XGPPDDIDDR Y