P24020 (AQN3_PIG) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Carbohydrate-binding protein AQN-3 Alternative name(s): Spermadhesin AQN-3 Zona pellucida-binding protein AQN-3
Organism	Sus scrofa (Pig) [Complete proteome]
Taxonomic identifier	9823 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Laurasiatheria › Cetartiodactyla › Suina › Suidae › Sus

Protein attributes

Sequence length	116 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	AQN proteins mediate the binding of boar spermatozoa to component(s) of the egg's zona pellucida by a carbohydrate-binding mechanism. AQN proteins are secretory components of the male accessory glands being coated to the sperm surface at the time of ejaculation. They possess as well heparin-, serine-protease-inhibitor-binding capability.
Subcellular location	Secreted.
Post-translational modification	The residue at position 85 was identified as a methylhistidine by mass spectrometry.
Sequence similarities	Belongs to the spermadhesin family. Contains 1 CUB domain.

Ontologies

Keywords
Biological process	Fertilization
Cellular component	Secreted
Ligand	Heparin-binding
PTM	Disulfide bond Glycoprotein Methylation
Technical term	Complete proteome Direct protein sequencing
Gene Ontology (GO)
Biological process	single fertilization Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	heparin 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
	Chain	1 – 116	116	Carbohydrate-binding protein AQN-3		PRO_0000221454
Regions
	Domain	9 – 110	102	CUB
Amino acid modifications
	Modified residue	85	1	Methylhistidine Probable
	Glycosylation	50	1	N-linked (GlcNAc...)
	Disulfide bond	9 ↔ 30		Ref.1
	Disulfide bond	53 ↔ 74		Ref.1
Experimental info
	Sequence conflict	79	1	F → T AA sequence Ref.3
	Sequence conflict	85	1	H → S AA sequence Ref.2

Sequences

	Sequence		Length	Mass (Da)
	P24020 [UniParc]. Last modified March 1, 1992. Version 1. Checksum: EC83E07A811D9FD3	FASTA	116	12,885
	10 20 30 40 50 60 AQNKGSDDCG GFLKNYSGWI SYYKALTTNC VWTIEMKPGH KIILQILPLN LTCGKEYLEV 70 80 90 100 110 RDQRAGPDNF LKVCGGTGFV YQSSHNVATV KYSRDSHHPA SSFNVYFYGI PQGAKA

References

[1]	"The amino acid sequence of AQN-3, a carbohydrate-binding protein isolated from boar sperm. Location of disulphide bridges." Sanz L., Calvete J.J., Mann K., Schaefer W., Schmid E.R., Toepfer-Petersen E. FEBS Lett. 291:33-36(1991) [PubMed: 1936247] [Abstract] Cited for: PROTEIN SEQUENCE, DISULFIDE BONDS, MASS SPECTROMETRY. Tissue: Sperm.
[2]	"Characterization of two glycosylated boar spermadhesins." Calvete J.J., Solis D., Sanz L., Diaz-Maurino T., Schaefer W., Mann K., Toepfer-Petersen E. Eur. J. Biochem. 218:719-725(1993) [PubMed: 8269963] [Abstract] Cited for: PROTEIN SEQUENCE. Tissue: Sperm.
[3]	"Mapping the heparin-binding domain of boar spermadhesins." Calvete J.J., Dostalova Z., Sanz L., Adermann K., Thole H.H., Toepfer-Petersen E. FEBS Lett. 379:207-211(1996) [PubMed: 8603690] [Abstract] Cited for: PROTEIN SEQUENCE OF 15-22 AND 79-84.
+	Additional computationally mapped references.

Cross-references

Sequence databases
PIR	S17567. S39434.
3D structure databases
ProteinModelPortal	P24020.
ModBase	Search...
Protein-protein interaction databases
STRING	P24020.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Phylogenomic databases
HOVERGEN	HBG004277.
OrthoDB	EOG4JQ400.
Family and domain databases
InterPro	IPR000859. CUB. IPR000124. Spermadhesin. [Graphical view]
Gene3D	G3DSA:2.60.120.290. CUB. 1 hit.
PANTHER	PTHR12222. Spermadhesin. 1 hit.
Pfam	PF00431. CUB. 1 hit. [Graphical view]
SMART	SM00042. CUB. 1 hit. [Graphical view]
SUPFAM	SSF49854. CUB. 1 hit.
PROSITE	PS01180. CUB. 1 hit. PS00985. SPERMADHESIN_1. 1 hit. PS00986. SPERMADHESIN_2. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

AQN3_PIG

Accession

Primary (citable) accession number: P24020

Entry history

Integrated into UniProtKB/Swiss-Prot:	March 1, 1992
Last sequence update:	March 1, 1992
Last modified:	September 21, 2011
This is version 65 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program