ID   ANT3_CHICK              Reviewed;         105 AA.
AC   Q03352;
DT   01-FEB-1994, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1994, sequence version 1.
DT   03-AUG-2022, entry version 96.
DE   RecName: Full=Antithrombin-III;
DE            Short=ATIII;
DE   AltName: Full=Serpin C1;
DE   Flags: Precursor; Fragment;
GN   Name=SERPINC1; Synonyms=AT3;
OS   Gallus gallus (Chicken).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Archelosauria; Archosauria; Dinosauria; Saurischia; Theropoda;
OC   Coelurosauria; Aves; Neognathae; Galloanserae; Galliformes; Phasianidae;
OC   Phasianinae; Gallus.
OX   NCBI_TaxID=9031;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=White leghorn; TISSUE=Liver;
RX   PubMed=8424948; DOI=10.1016/0167-4781(93)90061-h;
RA   Amrani D.L., Rosenberg J., Samad F., Bergtrom G., Banfield D.K.;
RT   "Developmental expression of chicken antithrombin III is regulated by
RT   increased RNA abundance and intracellular processing.";
RL   Biochim. Biophys. Acta 1171:239-246(1993).
RN   [2]
RP   PROTEIN SEQUENCE OF 18-36.
RX   PubMed=6920385; DOI=10.1093/oxfordjournals.jbchem.a133806;
RA   Koide T., Ohta Y., Odani S., Ono T.;
RT   "Chicken antithrombin. Isolation, characterization, and comparison with
RT   mammalian antithrombins and chicken ovalbumin.";
RL   J. Biochem. 91:1223-1229(1982).
CC   -!- FUNCTION: Most important serine protease inhibitor in plasma that
CC       regulates the blood coagulation cascade. AT-III inhibits thrombin,
CC       matriptase-3/TMPRSS7, as well as factors IXa, Xa and XIa. Its
CC       inhibitory activity is greatly enhanced in the presence of heparin (By
CC       similarity). {ECO:0000250}.
CC   -!- SUBUNIT: Forms protease inhibiting heterodimer with TMPRSS7.
CC       {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted, extracellular space {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Plasma.
CC   -!- SIMILARITY: Belongs to the serpin family. {ECO:0000305}.
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DR   EMBL; L07842; AAA49075.1; -; mRNA.
DR   PIR; S28177; S28177.
DR   AlphaFoldDB; Q03352; -.
DR   SMR; Q03352; -.
DR   VEuPathDB; HostDB:geneid_424440; -.
DR   Proteomes; UP000000539; Unplaced.
DR   GO; GO:0005615; C:extracellular space; IEA:UniProtKB-SubCell.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0007596; P:blood coagulation; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Blood coagulation; Direct protein sequencing; Hemostasis;
KW   Protease inhibitor; Reference proteome; Secreted;
KW   Serine protease inhibitor; Signal.
FT   SIGNAL          1..17
FT                   /evidence="ECO:0000269|PubMed:6920385"
FT   CHAIN           18..>105
FT                   /note="Antithrombin-III"
FT                   /id="PRO_0000032493"
FT   REGION          38..105
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   CONFLICT        31
FT                   /note="R -> T (in Ref. 2; AA sequence)"
FT                   /evidence="ECO:0000305"
FT   NON_TER         105
SQ   SEQUENCE   105 AA;  11281 MW;  9C01D1D38B1C5523 CRC64;
     MHLFIGVSLR PLGHGIPAPY AVEDICTAKP RDIPVNPICI YRNPEKKPQE RRGAGAGEGQ
     DPGVHKPPAS GSCPGPTRAF GRRSFLQAPG PTPRTMRRTS SCRPS