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Overview for MACiE Entry M0022

Version history

General Information

EC Number: 2.3.1.87 (A member of the Transferases, Acyltransferases, Transferring groups other than aminoacyl groups)

Enzyme Name: aralkylamine N-acetyltransferase

Biological Species: Ovis aries (Sheep)

Catalytic Chain UniprotKB Accession Codes:

  • Q29495 - Serotonin N-acetyltransferase

Representative PDB Code: 1b6b - MELATONIN BIOSYNTHESIS: THE STRUCTURE OF SEROTONIN N-ACETYLTRANSFERASE AT 2.5 A RESOLUTION SUGGESTS A CATALYTICMECHANISM (Resolution = 2.50 Å).

Catalytic CATH Codes:

Display structure information

Overall Reaction:

Image of 3-(2-aminoethyl)-indol-5-ol

Image of acetyl-CoA

right arrow

Image of proton

Image of CoA

Image of N-acetylserotonin

3-(2-aminoethyl)-indol-5-ol
C00780
CHEBI:350546
acetyl-CoA
C00024
CHEBI:57288
proton
C00080
CHEBI:24636
CoA
C00010
CHEBI:57287
N-acetylserotonin
C00978
CHEBI:17697

Overall Comment: There is some debates as to whether the Tyr168 or His120 is the other general acid/base catalyst.


View similar reactions


Stepwise Description of the Reaction

Step 1His122 deprotonates the amine of 3-(2-aminoethyl)-indol-5-ol, which initiates a nucleophilic attack on the carbonyl carbon of acyl-CoA in an addition reaction
Step 2The oxyanion collapses, eliminating CoA, which deprotonated Tyr168
Step 3Tyr168 deprotonates the secondary amine of the product.
Step 4Water deprotonates His122 in an inferred return step.

View similar reactions (composite manual annotation)


Catalytic Residues Involved

Type Number Chain Location of Function
Ser 97 A Side Chain
Leu 111 A Main Chain Carbonyl
His 122 A Side Chain
Leu 124 A Main Chain Amide
Tyr 168 A Side Chain

References

  1. A. B. Hickman et al. (1999), Mol. Cell, 3, 23-32. Melatonin biosynthesis: the structure of serotonin N-acetyltransferase at 2.5 A resolution suggests a catalytic mechanism.
    Medline: 10024876

Homologue information for M0022 (1b6b)

CSA Homologues

MACiE Homologues (within the PDB)

MACiE Homologues (within UniprotKB/SwissProt)



Entries with at least one Catalytic CATH code in common (different mechanisms):

MACiE Entry Enzyme Name
EC Number
PDB code CATH code Composite
Reaction Similarity
Catalytic Machinery
Similarity
M0224 histone acetyltransferase
2.3.1.48
1bob 3.40.630.30
0.250.0119Compare

Links to this entry in other databases

Link to EC-PDB-SUM Link to PDB-SUM Link to RCSB PDB Link to PDBe Link to CSA
Link to MetaCyc Link to KEGG Link to BRENDA Link to ExplorENZ
Link to EzCatDB

GOA logo
aralkylamine N-acetyltransferase activity (molecular function)
cytoplasm (cellular component)
N-acetyltransferase activity (molecular function)
metabolic process (biological process)
transferase activity (molecular function)
melatonin biosynthetic process (biological process)
rhythmic process (biological process)
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