Related Experiment Video
Updated: Feb 6, 2026

In vitro Methylation Assay to Study Protein Arginine Methylation
Published on: October 5, 2014
NRPS Protein MarQ Catalyzes Flexible Adenylation and Specific S-Methylation
Tingting Huang1, Yingyi Duan1, Yi Zou1
1State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology , Shanghai Jiao Tong University , Shanghai 200240 , China.
Abstract:
Maremycins are a group of structurally diverse 2,5-diketopiperazine natural products featuring a rare amino acid building block, S-methyl-l-cysteine (Me-Cys). Three freestanding nonribosomal peptide synthetase (NRPS) proteins from the maremycins biosynthetic pathway were proposed for the formation of the 2,5-diketopiperazine scaffold: MarQ, MarM, and MarJ. MarQ displays flexible adenylation activity toward Cys, Me-Cys, Ser, and ( S)-2,3-diaminopropanoic acid (DAP) and transfers these substrates to MarJ, which is the discrete peptidyl carrier protein (PCP). MarQ could also activate several other amino acids. The embedded methyltransferase (MT) domain in MarQ specifically catalyzes the thiol methylation of MarJ-tethered Cys. The in vitro reconstitution of MarQ and MarJ further provides clear evidence for the reaction sequence of methylation step on Cys. Our study on MarJ/Q tridomain cassette gains valuable insights into maremycins structure diversity and will be exploited to incorporate Me-Cys into natural products by combinatorial biosynthesis.
Related Concept Videos
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein....
Acid-Catalyzed Ring-Opening of Epoxides
Base-Catalyzed Ring-Opening of Epoxides
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Base-Catalyzed Aldol Addition Reaction

