P23807 (IXXB_PROFL) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Coagulation factor IX/factor X-binding protein subunit B Short name=IX/X-BP
Organism	Protobothrops flavoviridis (Habu) (Trimeresurus flavoviridis)
Taxonomic identifier	88087 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Lepidosauria › Squamata › Scleroglossa › Serpentes › Colubroidea › Viperidae › Crotalinae › Trimeresurus

Protein attributes

Sequence length	146 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	When linked to subunit A of IX/X-bp, anticoagulant protein which binds to the gamma-carboxyglutamic acid-domain regions of factors IX and factor X in the presence of calcium with a 1 to 1 stoichiometry. Ref.3 Ref.4 When linked to subunit A of IX-bp, anticoagulant protein which binds to the gamma-carboxyglutamic acid-domain regions of factor IX (but not to factor X) in the presence of calcium with a 1 to 1 stoichiometry. Ref.3 Ref.4
Subunit structure	Forms an heterodimer with subunit A of IX/X-bp or IX-bp; disulfide-linked. Ref.5 Ref.6 Ref.7 Ref.8
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Miscellaneous	Calcium is required for ligand binding.
Sequence similarities	Contains 1 C-type lectin domain.

Ontologies

Keywords
Biological process	Blood coagulation
Cellular component	Secreted
Domain	Signal
Ligand	Calcium Lectin Metal-binding
Molecular function	Toxin
PTM	Disulfide bond
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Biological process	blood coagulation Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW sugar binding Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Signal peptide

1 – 23

23

Ref.2

Chain

24 – 146

123

Coagulation factor IX/factor X-binding protein subunit B

PRO_0000017531

Regions

Domain

24 – 146

123

C-type lectin

Sites

Metal binding

64

1

Calcium; via carbonyl oxygen

Metal binding

66

1

Calcium

Metal binding

70

1

Calcium

Metal binding

143

1

Calcium

Amino acid modifications

Disulfide bond

25 ↔ 36

Ref.5 Ref.6 Ref.7 Ref.8

Disulfide bond

53 ↔ 142

Ref.5 Ref.6 Ref.7 Ref.8

Disulfide bond

98

Interchain (with C-102 in subunit A of IX/X-bp or with C-79 in subunit A of IX-bp) Ref.5 Ref.6 Ref.7 Ref.8

Disulfide bond

119 ↔ 134

Ref.5 Ref.6 Ref.7 Ref.8

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

146

Helix Strand Turn

Details...

Beta strand

29 – 32

4

Beta strand

35 – 44

10

Helix

46 – 56

11

Helix

68 – 82

15

Beta strand

86 – 88

3

Beta strand

100 – 102

3

Beta strand

118 – 123

6

Beta strand

129 – 133

5

Beta strand

138 – 145

8

Sequences

	Sequence		Length	Mass (Da)
	P23807 [UniParc]. Last modified July 15, 1998. Version 2. Checksum: 8E1961C59F96757C	FASTA	146	16,922
	10 20 30 40 50 60 MGRFIFMSFG FLVVFLSLSG TAADCPSDWS SYEGHCYKPF SEPKNWADAE NFCTQQHAGG 70 80 90 100 110 120 HLVSFQSSEE ADFVVKLAFQ TFGHSIFWMG LSNVWNQCNW QWSNAAMLRY KAWAEESYCV 130 140 YFKSTNNKWR SRACRMMAQF VCEFQA

References

[1]	"cDNA cloning of IX/X-BP, a heterogeneous two-chain anticoagulant protein from snake venom." Matsuzaki R., Yoshihara E., Yamada M., Shima K., Atoda H., Morita T. Biochem. Biophys. Res. Commun. 220:382-387(1996) [PubMed: 8645314] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Venom gland.
[2]	"The primary structure of coagulation factor IX/factor X-binding protein isolated from the venom of Trimeresurus flavoviridis. Homology with asialoglycoprotein receptors, proteoglycan core protein, tetranectin, and lymphocyte Fc epsilon receptor for immunoglobulin E." Atoda H., Hyuga M., Morita T. J. Biol. Chem. 266:14903-14911(1991) [PubMed: 1831197] [Abstract] Cited for: PROTEIN SEQUENCE OF 24-146. Tissue: Venom.
[3]	"Binding properties of the coagulation factor IX/factor X-binding protein isolated from the venom of Trimeresurus flavoviridis." Atoda H., Yoshida N., Ishikawa M., Morita T. Eur. J. Biochem. 224:703-708(1994) [PubMed: 7925387] [Abstract] Cited for: FUNCTION.
[4]	"Blood coagulation factor IX-binding protein from the venom of Trimeresurus flavoviridis: purification and characterization." Atoda H., Ishikawa M., Yoshihara E., Sekiya F., Morita T. J. Biochem. 118:965-973(1995) [PubMed: 8749314] [Abstract] Cited for: FUNCTION. Tissue: Venom.
[5]	"Structure of coagulation factors IX/X-binding protein, a heterodimer of C-type lectin domains." Mizuno H., Fujimoto Z., Koizumi M., Kano H., Atoda H., Morita T. Nat. Struct. Biol. 4:438-441(1997) [PubMed: 9187649] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.5 ANGSTROMS) OF 24-146 IN DIMER WITH IX/X-BP, METAL-BINDING SITES, DISULFIDE BONDS.
[6]	"Crystal structure of coagulation factor IX-binding protein from habu snake venom at 2.6 A: implication of central loop swapping based on deletion in the linker region." Mizuno H., Fujimoto Z., Koizumi M., Kano H., Atoda H., Morita T. J. Mol. Biol. 289:103-112(1999) [PubMed: 10339409] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.6 ANGSTROMS) OF 24-146 IN DIMER WITH IX-BP, METAL-BINDING SITES, DISULFIDE BONDS.
[7]	"Crystal structure of Mg2+- and Ca2+-bound Gla domain of factor IX complexed with binding protein." Shikamoto Y., Morita T., Fujimoto Z., Mizuno H. J. Biol. Chem. 278:24090-24094(2003) [PubMed: 12695512] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.55 ANGSTROMS) OF 24-146 IN DIMER WITH IX-BP, METAL-BINDING SITES, DISULFIDE BONDS.
[8]	"pH-dependent structural changes at Ca(2+)-binding sites of coagulation factor IX-binding protein." Suzuki N., Fujimoto Z., Morita T., Fukamizu A., Mizuno H. J. Mol. Biol. 353:80-87(2005) [PubMed: 16165155] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.72 ANGSTROMS) OF 24-146 IN DIMER WITH IX-BP, METAL-BINDING SITES, DISULFIDE BONDS.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

D83332 mRNA. Translation: BAA11888.1.

PIR

JC4691.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1BJ3	X-ray	2.60	B	24-146	[»]
1IXX	X-ray	2.50	B/D/F	24-146	[»]
1J34	X-ray	1.55	B	24-146	[»]
1J35	X-ray	1.80	B	24-146	[»]
1X2T	X-ray	1.72	B/D	24-146	[»]
1X2W	X-ray	2.29	B	24-146	[»]

ProteinModelPortal

P23807.

SMR

P23807. Positions 24-146.

ModBase

Search...

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Phylogenomic databases

HOVERGEN

HBG004151.

Family and domain databases

InterPro

IPR001304. C-type_lectin.
IPR016186. C-type_lectin-like.
IPR018378. C-type_lectin_CS.
IPR016187. C-type_lectin_fold.
IPR003990. Pancreatis_ac.
[Graphical view]

Gene3D

G3DSA:3.10.100.10. C-type_lectin-like. 1 hit.

Pfam

PF00059. Lectin_C. 1 hit.
[Graphical view]

PRINTS

PR01504. PNCREATITSAP.

SMART

SM00034. CLECT. 1 hit.
[Graphical view]

SUPFAM

SSF56436. C-type_lectin_fold. 1 hit.

PROSITE

PS00615. C_TYPE_LECTIN_1. 1 hit.
PS50041. C_TYPE_LECTIN_2. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

IXXB_PROFL

Accession

Primary (citable) accession number: P23807
Secondary accession number(s): Q91247

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1991
Last sequence update:	July 15, 1998
Last modified:	September 21, 2011
This is version 78 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program

Annotation program

Chordata Protein Annotation Program