Acetylserotonin O-methyltransferase (IPR025781)

Short name: AS_MeTrfase

Family relationships


This entry represents acetylserotonin O-methyltransferase (EC:, which produces melatonin (N-acetyl-5-methoxytryptamine) from N-acetylserotonin. The enzyme is expressed at high levels in the pineal gland [PMID: 3818627, PMID: 8574683]. Acetylserotonin O-methyltransferase, along with other enzymes involved in melatonin synthesis, is expressed with a day/night rhythm [PMID: 10420435] and is transcriptionally regulated by circadian oscillators and photosensory mechanisms [PMID: 8920978].

Methyltransferases (EC 2.1.1.-) constitute an important class of enzymes present in every life form. They transfer a methyl group most frequently from S-adenosyl L-methionine (SAM or AdoMet) to a nucleophilic acceptor such as oxygen leading to S-adenosyl-L-homocysteine (AdoHcy) and a methylated molecule [PMID: 16225687, PMID: 21858014, PMID: 12826405]. All these enzymes have in common a conserved region of about 130 amino acid residues that allow them to bind SAM [PMID: 7897657]. The substrates that are methylated by these enzymes cover virtually every kind of biomolecules ranging from small molecules, to lipids, proteins and nucleic acids [PMID: 16225687, PMID: 21858014, PMID: 7897657]. Methyltransferase are therefore involved in many essential cellular processes including biosynthesis, signal transduction, protein repair, chromatin regulation and gene silencing [PMID: 16225687, PMID: 21858014, PMID: 12826405]. More than 230 families of methyltransferases have been described so far, of which more than 220 use SAM as the methyl donor.

GO terms

Biological Process

GO:0030187 melatonin biosynthetic process

Molecular Function

GO:0008171 O-methyltransferase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles