ID   FIBA_BISBO              Reviewed;          19 AA.
AC   P14441;
DT   01-JAN-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1990, sequence version 1.
DT   25-MAY-2022, entry version 51.
DE   RecName: Full=Fibrinogen alpha chain;
DE   Contains:
DE     RecName: Full=Fibrinopeptide A;
DE   Flags: Fragment;
GN   Name=FGA;
OS   Bison bonasus (European bison).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Artiodactyla; Ruminantia; Pecora; Bovidae;
OC   Bovinae; Bison.
OX   NCBI_TaxID=9902;
RN   [1]
RP   PROTEIN SEQUENCE.
RA   Blombaeck B., Blombaeck M., Grondahl N.J.;
RT   "Studies on fibrinopeptides from mammals.";
RL   Acta Chem. Scand. 19:1789-1791(1965).
CC   -!- FUNCTION: Cleaved by the protease thrombin to yield monomers which,
CC       together with fibrinogen beta (FGB) and fibrinogen gamma (FGG),
CC       polymerize to form an insoluble fibrin matrix. Fibrin has a major
CC       function in hemostasis as one of the primary components of blood clots.
CC       In addition, functions during the early stages of wound repair to
CC       stabilize the lesion and guide cell migration during re-
CC       epithelialization. Was originally thought to be essential for platelet
CC       aggregation, based on in vitro studies using anticoagulated blood.
CC       However, subsequent studies have shown that it is not absolutely
CC       required for thrombus formation in vivo. Enhances expression of SELP in
CC       activated platelets via an ITGB3-dependent pathway. Maternal fibrinogen
CC       is essential for successful pregnancy. Fibrin deposition is also
CC       associated with infection, where it protects against IFNG-mediated
CC       hemorrhage. May also facilitate the immune response via both innate and
CC       T-cell mediated pathways. {ECO:0000250|UniProtKB:E9PV24}.
CC   -!- SUBUNIT: Heterohexamer; disulfide linked. Contains 2 sets of 3 non-
CC       identical chains (alpha, beta and gamma). The 2 heterotrimers are in
CC       head to head conformation with the N-termini in a small central domain
CC       (By similarity). {ECO:0000250|UniProtKB:P02671}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- DOMAIN: A long coiled coil structure formed by 3 polypeptide chains
CC       connects the central nodule to the C-terminal domains (distal nodules).
CC       The long C-terminal ends of the alpha chains fold back, contributing a
CC       fourth strand to the coiled coil structure.
CC       {ECO:0000250|UniProtKB:P02671}.
CC   -!- PTM: Conversion of fibrinogen to fibrin is triggered by thrombin, which
CC       cleaves fibrinopeptides A and B from alpha and beta chains, and thus
CC       exposes the N-terminal polymerization sites responsible for the
CC       formation of the soft clot. The soft clot is converted into the hard
CC       clot by factor XIIIA which catalyzes the epsilon-(gamma-glutamyl)lysine
CC       cross-linking between gamma chains (stronger) and between alpha chains
CC       (weaker) of different monomers.
CC   -!- PTM: Forms F13A-mediated cross-links between a glutamine and the
CC       epsilon-amino group of a lysine residue, forming fibronectin-fibrinogen
CC       heteropolymers.
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DR   AlphaFoldDB; P14441; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0002250; P:adaptive immune response; IEA:UniProtKB-KW.
DR   GO; GO:0007596; P:blood coagulation; IEA:UniProtKB-KW.
DR   GO; GO:0045087; P:innate immune response; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Adaptive immunity; Blood coagulation; Coiled coil;
KW   Direct protein sequencing; Disulfide bond; Hemostasis; Immunity;
KW   Innate immunity; Secreted.
FT   PEPTIDE         1..19
FT                   /note="Fibrinopeptide A"
FT                   /id="PRO_0000009004"
FT   NON_TER         19
SQ   SEQUENCE   19 AA;  1836 MW;  9BA55A0F473B59C5 CRC64;
     EDGSDPASGD FLAEGGGVR