Related Experiment Video
Updated: Jun 11, 2026

Antibody-Free Assay for RNA Methyltransferase Activity Analysis
Published on: July 9, 2019
Two O-methyltransferases from Picea abies: characterization and molecular basis of different reactivity
Bong-Gyu Kim1, Dae Hwan Kim, Su Hyun Sung
1Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul, Korea.
Abstract:
O-Methyltransferase (OMT) catalyzes the transfer of a methyl group from S-adenosyl methionine (SAM) to hydroxyl groups of methyl acceptors. Two OMTs, PaOMT2 and PaOMT3, from Picea abies showed 93.5% identity at the amino acid level. However, PaOMT3 catalyzed the reaction more efficiently than PaOMT2 with several phenolic compounds, including quercetin and caffeoyl-CoA. To determine the critical amino acids for the different reactivity of the two OMTs, site-directed mutagenesis was carried out. The amino acid proline at position 35 in PaOMT2 and leucine in PaOMT3 is a critical amino acid for their reactivity. Molecular modeling showed that the sequential change triggered by Leu35 resulted in a change in the size of the substrate binding pocket, which could account for the different catalytic reactivity of two OMTs.
Related Concept Videos
Phase II Reactions: Methylation Reactions
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
RNA Editing
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Ligand Binding and Linkage

