Related Experiment Video
Updated: Sep 29, 2025

Thermostabilization, Expression, Purification, and Crystallization of the Human Serotonin Transporter Bound to S-citalopram
Published on: November 27, 2016
Functional Characterization of Serotonin N-Acetyltransferase in Archaeon Thermoplasma volcanium
Kyungjin Lee1, Geun-Hee Choi2, Kyoungwhan Back1
1Department of Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea.
Abstract:
Serotonin N-acetyltransferase is the penultimate enzyme in the melatonin biosynthetic pathway that catalyzes serotonin into N-acetylserotonin. Many SNAT genes have been cloned and characterized from organisms ranging from bacteria to plants and mammals. However, to date, no SNAT gene has been identified from Archaea. In this study, three archaeal SNAT candidate genes were synthesized and expressed in Escherichia coli, and SNAT enzyme activity was measured using their purified recombinant proteins. Two SNAT candidate genes, from Methanoregulaceae (Archaea) and Pyrococcus furiosus, showed no SNAT enzyme activity, whereas a SNAT candidate gene from Thermoplasma volcanium previously named TvArd1 exhibited SNAT enzyme activity. The substrate affinity and the maximum reaction rate of TvSNAT toward serotonin were 621 μM and 416 pmol/min/mg protein, respectively. The highest amine substrate was tyramine, followed by tryptamine, serotonin, and 5-methoxytryptamine, which were similar to those of plant SNAT enzymes. Homologs of TvSNAT were found in many Archaea families. Ectopic overexpression of TvSNAT in rice resulted in increased melatonin content, antioxidant activity, and seed size in conjunction with the enhanced expression of seed size-related gene. This study is the first to report the discovery of SNAT gene in Archaea. Future research avenues include the cloning of TvSNAT orthologs in different phyla, and identification of their regulation and functions related to melatonin biosynthesis in living organisms.
More Related Videos
09:31PCR Mutagenesis, Cloning, Expression, Fast Protein Purification Protocols and Crystallization of the Wild Type and Mutant Forms of Tryptophan Synthase
Published on: September 26, 2020
12:36In vitro tRNA Methylation Assay with the Entamoeba histolytica DNA and tRNA Methyltransferase Dnmt2 Ehmeth Enzyme
Published on: October 19, 2010
Related Concept Videos
Hyperthermophilic Bacteria
Diversity of Archaea IV
Diversity of Archaea III
Tail-anchoring of Proteins in the ER Membrane
tRNA Activation
Diversity of Archaea I