Q5H879 (COMT_HORSE) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Catechol O-methyltransferase
EC=2.1.1.6

Gene names

Name:

COMT

Organism

Equus caballus (Horse) [Reference proteome]

Taxonomic identifier

9796 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Laurasiatheria › Perissodactyla › Equidae › Equus › Equus

Protein attributes

Sequence length	269 AA.
Sequence status	Complete.
Protein existence	Evidence at transcript level

General annotation (Comments)

Function	Catalyzes the O-methylation, and thereby the inactivation, of catecholamine neurotransmitters and catechol hormones. Also shortens the biological half-lives of certain neuroactive drugs, like L-DOPA, alpha-methyl DOPA and isoproterenol By similarity.
Catalytic activity	S-adenosyl-L-methionine + a catechol = S-adenosyl-L-homocysteine + a guaiacol.
Cofactor	Binds 1 magnesium ion per subunit By similarity.
Subcellular location	Isoform 2: Cytoplasm By similarity. Isoform 1: Cell membrane; Single-pass type II membrane protein; Extracellular side By similarity.
Sequence similarities	Belongs to the methyltransferase superfamily. Catechol-O-methyltransferase family.

Ontologies

Keywords
Biological process	Catecholamine metabolism Neurotransmitter degradation
Cellular component	Cell membrane Cytoplasm Membrane
Coding sequence diversity	Alternative initiation Polymorphism
Domain	Signal-anchor Transmembrane Transmembrane helix
Ligand	Magnesium Metal-binding S-adenosyl-L-methionine
Molecular function	Methyltransferase Transferase
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Biological_process	catecholamine metabolic process Inferred from electronic annotation. Source: UniProtKB-KW neurotransmitter catabolic process Inferred from electronic annotation. Source: UniProtKB-KW
Cellular_component	cytoplasm Inferred from electronic annotation. Source: UniProtKB-SubCell integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW plasma membrane Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular_function	catechol O-methyltransferase activity Inferred from electronic annotation. Source: EC magnesium ion binding Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative initiation. [Align] [Select]

Isoform 1 (identifier: Q5H879-1)

Also known as: Membrane-bound; MB-COMT;

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Isoform 2 (identifier: Q5H879-2)

Also known as: Soluble; S-COMT;

The sequence of this isoform differs from the canonical sequence as follows:
     1-47: Missing.

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 269	269	Catechol O-methyltransferase		PRO_0000318147
Regions
	Transmembrane	5 – 25	21	Helical; Signal-anchor for type II membrane protein; Potential
	Region	164 – 167	4	S-adenosyl-L-methionine binding By similarity
Sites
	Metal binding	188	1	Magnesium By similarity
	Metal binding	216	1	Magnesium By similarity
	Metal binding	217	1	Magnesium By similarity
	Binding site	89	1	S-adenosyl-L-methionine; via amide nitrogen By similarity
	Binding site	119	1	S-adenosyl-L-methionine By similarity
	Binding site	137	1	S-adenosyl-L-methionine By similarity
	Binding site	188	1	S-adenosyl-L-methionine By similarity
	Binding site	191	1	Substrate By similarity
	Binding site	217	1	Substrate By similarity
	Binding site	246	1	Substrate By similarity
Natural variations
	Alternative sequence	1 – 47	47	Missing in isoform 2.		VSP_031176
	Natural variant	120	1	A → T. Ref.1

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 (Membrane-bound) (MB-COMT) [UniParc]. Last modified March 1, 2005. Version 1. Checksum: 73A24585C6768C44	FASTA	269	30,028
	10 20 30 40 50 60 MLEPTPMLLA AFSLGLALLP LLFFLRRWGW LLIGWNECIL QPIHNLLMGD SKEQRILRHV 70 80 90 100 110 120 LQHAVAGDPQ SVLETIDAYC SQKEWAMNVG DKKGQFLDAV VQEQQPSVLL ELGAYCGYSA 130 140 150 160 170 180 VRMARLLPPG ARLLTIEINP DYAAITQRML DFAGLQDRVT VVLGASQDII PQLKKKYDVD 190 200 210 220 230 240 TLDVVFLDHW KDRYLPDTLL LEECGLLRKG TVLLADNVIV PGAPDFLAHV RGSGRFECTH 250 260 FSSYLEYSLW VVDGVEKAVY LGPGSPAQP
	Isoform 2 (Soluble) (S-COMT) [UniParc]. Checksum: 4E3097D0491A0103	FASTA	222	24,600
	10 20 30 40 50 60 MGDSKEQRIL RHVLQHAVAG DPQSVLETID AYCSQKEWAM NVGDKKGQFL DAVVQEQQPS 70 80 90 100 110 120 VLLELGAYCG YSAVRMARLL PPGARLLTIE INPDYAAITQ RMLDFAGLQD RVTVVLGASQ 130 140 150 160 170 180 DIIPQLKKKY DVDTLDVVFL DHWKDRYLPD TLLLEECGLL RKGTVLLADN VIVPGAPDFL 190 200 210 220 AHVRGSGRFE CTHFSSYLEY SLWVVDGVEK AVYLGPGSPA QP

References

[1]

"Sequence, detection of polymorphisms and radiation hybrid mapping of the equine catechol-O-methyltransferase gene." Momozawa Y., Takeuchi Y., Tozaki T., Kikusui T., Hasegawa T., Raudsepp T., Chowdhary B.P., Kusunose R., Mori Y. Anim. Genet. 36:190-190(2005) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], VARIANT THR-120, ALTERNATIVE INITIATION.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AB178284 mRNA. Translation: BAD89294.1. AB178284 mRNA. Translation: BAD89295.1.
RefSeq	NP_001075303.1. NM_001081834.1. NP_001108007.1. NM_001114535.1.
UniGene	Eca.6385.
3D structure databases
HSSP	HSSP built from PDB template 1H1D based on UniProtKB P22734.
ProteinModelPortal	Q5H879.
SMR	Q5H879. Positions 49-263.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	100146509.
KEGG	ecb:100146509.
Organism-specific databases
CTD	1312.
Phylogenomic databases
eggNOG	COG4122.
HOGENOM	HOG000046392.
HOVERGEN	HBG005376.
InParanoid	Q5H879.
KO	K00545.
OrthoDB	EOG4G1MH8.
Family and domain databases
InterPro	IPR025782. Catechol_O-MeTrfase. IPR017128. Catechol_O-MeTrfase_euk. IPR002935. O-MeTrfase_3. [Graphical view]
PANTHER	PTHR10509. PTHR10509. 1 hit.
Pfam	PF01596. Methyltransf_3. 1 hit. [Graphical view]
PIRSF	PIRSF037177. Catechol_O-mtfrase_euk. 1 hit.
ProtoNet	Search...

Entry information

Entry name

COMT_HORSE

Accession

Primary (citable) accession number: Q5H879
Secondary accession number(s): Q5H878

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 5, 2008
Last sequence update:	March 1, 2005
Last modified:	March 6, 2013
This is version 64 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program