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Reviewed, UniProtKB/Swiss-Prot P00740 (FA9_HUMAN)

Last modified July 22, 2008. Version 139. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (9) | Third-party data | Customize display text xml rdf/xml gff fasta
Names and origin · Protein attributes · General annotation (Comments) · Ontologies · Sequence annotation (Features) · Sequences · References · Web resources · Cross-references · Entry information · Relevant documents

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Names and origin

Protein namesRecommended name:
    Coagulation factor IX
    EC=3.4.21.22
Alternative name(s):
    Christmas factor
    Plasma thromboplastin component
      Short name=PTC
Cleaved into the following 2 chains:
    1- Recommended name:
            Coagulation factor IXa light chain
    2- Recommended name:
            Coagulation factor IXa heavy chain
Gene names
Name: F9
OrganismHomo sapiens (Human)
Taxonomic identifier9606 [NCBI]
Taxonomic lineageEukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo

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Protein attributes

Sequence length461 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level.

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General annotation (Comments)

Function

Factor IX is a vitamin K-dependent plasma protein that participates in the intrinsic pathway of blood coagulation by converting factor X to its active form in the presence of Ca(2+) ions, phospholipids, and factor VIIIa.

Catalytic activity

Selective cleavage of Arg-|-Ile bond in factor X to form factor Xa.

Subunit structure

Heterodimer of a light chain and a heavy chain; disulfide-linked.

Subcellular location

Secreted.

Tissue specificity

Synthesized primarily in the liver and secreted in plasma.

Domain

Calcium binds to the gamma-carboxyglutamic acid (Gla) residues and, with stronger affinity, to another site, beyond the Gla domain.

Post-translational modification

Activated by factor XIa, which excises the activation peptide.

Involvement in disease

Defects in F9 are the cause of recessive X-linked hemophilia B (HEMB) [MIM:306900]; also known as Christmas disease.

Mutations in position 43 (Oxford-3, San Dimas) and 46 (Cambridge) prevents cleavage of the propeptide, mutation in position 93 (Alabama) probably fails to bind to cell membranes, mutation in position 191 (Chapel-Hill) or in position 226 (Nagoya OR Hilo) prevent cleavage of the activation peptide.

Pharmaceutical use

Available under the names BeneFix (Baxter and American Home Products). Used to treat hemophilia B.

Miscellaneous

In 1952, one of the earliest researchers of the disease, Dr. R.G. Macfarlane used the patient's surname, Christmas, to refer to the disease and also to refer to the clotting factor which he called the 'Christmas Factor' At the time Stephen Christmas was a 5-year-old boy. He died in 1993 at the age of 46 from acquired immunodeficiency syndrome contracted through treatment with blood products.

Sequence similarities

Belongs to the peptidase S1 family.

Contains 2 EGF-like domains.

Contains 1 Gla (gamma-carboxy-glutamate) domain.

Contains 1 peptidase S1 domain.

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Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical view

Molecule processing

Signal peptide1 – 2828 Potential
Propeptide29 – 4618
Chain47 – 461415Coagulation factor IX
Chain47 – 191145Coagulation factor IXa light chain
Propeptide192 – 22635Activation peptide
Chain227 – 461235Coagulation factor IXa heavy chain

Regions

Domain47 – 9246Gla
Domain93 – 12937EGF-like 1; calcium-binding Potential
Domain130 – 17142EGF-like 2
Domain227 – 459233Peptidase S1

Sites

Active site2671Charge relay system
Active site3151Charge relay system
Active site4111Charge relay system
Site191 – 1922Cleavage; by factor XIa
Site226 – 2272Cleavage; by factor XIa

Amino acid modifications

Modified residue5314-carboxyglutamate
Modified residue5414-carboxyglutamate
Modified residue6114-carboxyglutamate
Modified residue6314-carboxyglutamate
Modified residue6614-carboxyglutamate
Modified residue6714-carboxyglutamate
Modified residue7214-carboxyglutamate
Modified residue7314-carboxyglutamate
Modified residue7614-carboxyglutamate
Modified residue7914-carboxyglutamate
Modified residue8214-carboxyglutamate
Modified residue8614-carboxyglutamate
Modified residue11013-hydroxyaspartate
Modified residue1141Phosphoserine
Modified residue2011Sulfotyrosine
Modified residue2041Phosphoserine
Glycosylation991O-linked (Glc...)
Glycosylation1071O-linked (Fuc...)
Glycosylation2031N-linked (GlcNAc...)
Glycosylation2051O-linked (GalNAc...)
Glycosylation2131N-linked (GlcNAc...)
Glycosylation2151O-linked (GalNAc...)
Disulfide bond64 ↔ 69
Disulfide bond97 ↔ 108
Disulfide bond102 ↔ 117
Disulfide bond119 ↔ 128
Disulfide bond134 ↔ 145
Disulfide bond141 ↔ 155
Disulfide bond157 ↔ 170
Disulfide bond178 ↔ 335
Disulfide bond252 ↔ 268
Disulfide bond382 ↔ 396
Disulfide bond407 ↔ 435

Natural variations

Natural variant71I → F
Natural variant171I → N in HEMB; severe; UK 22.
Natural variant281C → R in HEMB; moderate; HB130.
Natural variant281C → Y in HEMB.
Natural variant301V → I in HEMB.
Natural variant371A → T in warfarin sensitivity; reduced affinity of the glutamate carboxylase for the factor IX precursor.
Natural variant431R → L in HEMB; severe; Bendorf, Beuten, Gleiwitz, etc..
Natural variant431R → Q in HEMB; severe; San Dimas, Oxford-3, Strasbourg-2, etc..
Natural variant431R → W in HEMB; severe; Boxtel, Heiden, Lienen, etc..
Natural variant451K → N in HEMB; severe; Seattle E.
Natural variant461R → S in HEMB; severe; Cambridge.
Natural variant461R → T in HEMB; severe.
Natural variant481N → I in HEMB; severe; Calgary-16.
Natural variant491S → P in HEMB.
Natural variant521L → S in HEMB; severe; Gla mutant.
Natural variant531E → A in HEMB; severe; Oxford-B2; Gla mutant.
Natural variant541E → G in HEMB; severe; HB151; Gla mutant.
Natural variant551F → C in HEMB.
Natural variant581G → A in HEMB; severe; Hong Kong-1.
Natural variant581G → R in HEMB; severe; Los Angeles-4.
Natural variant62 – 632Missing in HEMB; severe.
Natural variant661E → V in HEMB; moderate.
Natural variant671E → K in HEMB; severe; Nagoya-4; Gla mutant.
Natural variant711F → S in HEMB; severe.
Natural variant731E → K in HEMB; severe; Seattle-3; Gla mutant.
Natural variant731E → V in HEMB; severe; Chongqing; Gla mutant.
Natural variant751R → Q in HEMB; mild.
Natural variant791E → D in HEMB.
Natural variant841T → R in HEMB.
Natural variant911Y → C in HEMB; moderate.
Natural variant931D → G in HEMB; moderate; Alabama.
Natural variant961Q → P in HEMB; severe; New London.
Natural variant971C → S in HEMB.
Natural variant1011P → R in HEMB.
Natural variant1021C → R in HEMB; severe; Basel.
Natural variant1061G → D in HEMB.
Natural variant1061G → S in HEMB; mild; Durham.
Natural variant1081C → S in HEMB.
Natural variant1101D → N in HEMB; severe; Oxford-D1.
Natural variant1121I → S in HEMB.
Natural variant1131N → K in HEMB; mild.
Natural variant1151Y → C in HEMB; severe.
Natural variant1191C → F in HEMB; severe.
Natural variant1191C → R in HEMB; Iran.
Natural variant1241E → K in HEMB.
Natural variant1251G → E in HEMB.
Natural variant1251G → R in HEMB.
Natural variant1251G → V in HEMB.
Natural variant129 – 1302Missing in HEMB.
Natural variant1341C → Y in HEMB.
Natural variant1361I → T in HEMB; mild.