Publication Abstract from PubMed
Serotonin N-acetyltransferase, a member of the GNAT acetyltransferase superfamily, is the penultimate enzyme in the conversion of serotonin to melatonin, the circadian neurohormone. Comparison of the structures of the substrate-free enzyme and the complex with a bisubstrate analog, coenzyme A-S-acetyltryptamine, demonstrates that acetyl coenzyme A (AcCoA) binding is accompanied by a large conformational change that in turn leads to the formation of the serotonin-binding site. The structure of the complex also provides insight into how the enzyme may facilitate acetyl transfer. A water-filled channel leading from the active site to the surface provides a pathway for proton removal following amine deprotonation. Furthermore, structural and mutagenesis results indicate an important role for Tyr-168 in catalysis.
The structural basis of ordered substrate binding by serotonin N-acetyltransferase: enzyme complex at 1.8 A resolution with a bisubstrate analog.,Hickman AB, Namboodiri MA, Klein DC, Dyda F Cell. 1999 Apr 30;97(3):361-9. PMID:10319816[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
