Structural highlights
Function
[DNAT_DROME] Catalyzes N-acetylation of tryptamine, tyramine, dopamine, serotonin and octopamine. Is not essential for sclerotization.[1] [2] [3]
Publication Abstract from PubMed
The daily cycle of melatonin biosynthesis in mammals is regulated by arylalkylamine N-acetyltransferase (EC 2.3.1.87, AANAT), making it an attractive target for therapeutic control of abnormal melatonin production in mood and sleep disorders. Drosophila melanogaster dopamine N-acetyltransferase (Dat) is an AANAT. Until this report, no insect Dat structure had been solved, and consequently, the structural basis for its acetyl-transfer activity was not well understood. We report herein the high-resolution crystal structure for a D. melanogaster Dat/acetyl coenzyme A (AcCoA) complex obtained using one-edge (Selenium) single-wavelength anomalous diffraction. The binding study by isothermal titration calorimetry suggested that the cofactor bound to Dat first before substrate. Examination of the complex structure and a substrate-docked model indicated that Dat contains a novel AANAT catalytic triad. A site-directed mutagenesis, a kinetic study and pH-rate profiles confirmed that Glu47, Ser182, and Ser186 were critical for catalysis. Collectively, our results suggest that Dat possesses a specialized active site structure dedicated to a catalytic mechanism.
Crystal Structure of Dopamine N-Acetyltransferase/Acetyl Coenzyme A Complex Provide Insights into the Catalytic Mechanism.,Cheng KC, Liao JN, Lyu PC Biochem J. 2012 Jun 21. PMID:22716280[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hintermann E, Grieder NC, Amherd R, Brodbeck D, Meyer UA. Cloning of an arylalkylamine N-acetyltransferase (aaNAT1) from Drosophila melanogaster expressed in the nervous system and the gut. Proc Natl Acad Sci U S A. 1996 Oct 29;93(22):12315-20. PMID:8901578
- ↑ Brodbeck D, Amherd R, Callaerts P, Hintermann E, Meyer UA, Affolter M. Molecular and biochemical characterization of the aaNAT1 (Dat) locus in Drosophila melanogaster: differential expression of two gene products. DNA Cell Biol. 1998 Jul;17(7):621-33. PMID:9703021
- ↑ Hintermann E, Jeno P, Meyer UA. Isolation and characterization of an arylalkylamine N-acetyltransferase from Drosophila melanogaster. FEBS Lett. 1995 Nov 13;375(1-2):148-50. PMID:7498465
- ↑ Cheng KC, Liao JN, Lyu PC. Crystal Structure of Dopamine N-Acetyltransferase/Acetyl Coenzyme A Complex Provide Insights into the Catalytic Mechanism. Biochem J. 2012 Jun 21. PMID:22716280 doi:10.1042/BJ20120520
