22OW

Crystal structure of O-adenosylmethionine-dependent methyltransferase McbD in complex with SAH

Summary for 22OW

• Entry DOI: 10.2210/pdb22ow/pdb
• Descriptor: Methyltransferase, S-ADENOSYL-L-HOMOCYSTEINE (2 entities in total)
• Functional Keywords: methyltransferase, marinacarboline b, transferase
• Biological source: Marinactinospora thermotolerans
• Total number of polymer chains: 2
• Total formula weight: 102435.13

Authors

Qiao, Z.,Teng, Y.B. (deposition date: 2026-01-19, release date: 2026-07-08)

Primary citation

Qiao, Z.,Yang, X.,Liu, J.,Liu, L.,Meng, X.,He, X.,Liu, G.,Teng, Y.B.,Chen, Q.
Structural and Mechanistic Insights into the O ‐Methyltransferase McbD in Marinacarboline Biosynthesis.
Acs Omega, 11:34350-34356, 2026

PubMed Abstract: -Methylation represents a prevalent tailoring modification in natural product biosynthesis, significantly altering molecular properties and bioactivity. In this study, we report the crystal structure of the -methyltransferase (MTase) McbD in complex with -adenosyl-l-homocysteine (SAH) at 3.0 Å resolution, complemented by a modeled binding pose for the substrate marinacarboline B (). Through integrated site-directed mutagenesis and enzymatic assays, we identified critical residues required for catalytic activity and propose a refined mechanistic model for methyl transfer. These findings offer substantive structural and mechanistic insights into how -MTases drive the diversification of bioactive natural products.

PubMed: 42326699
DOI: 10.1021/acsomega.6c02087

Experimental method

X-RAY DIFFRACTION (3 Å)