6P3N

Tetrahydroprotoberberine N-methyltransferase in complex with S-adenosylmethionine

6P3N の概要

• エントリーDOI: 10.2210/pdb6p3n/pdb
• 分子名称: tetrahydroprotoberberine N-methyltransferase, S-ADENOSYLMETHIONINE (3 entities in total)
• 機能のキーワード: methyltransferase, transferase
• 由来する生物種: Glaucium flavum
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 44200.36

構造登録者

Lang, D.E.,Morris, J.S.,Rowley, M.,Torres, M.A.,Maksimovich, V.A.,Facchini, P.J.,Ng, K.K.S. (登録日: 2019-05-24, 公開日: 2019-08-14, 最終更新日: 2023-10-11)

主引用文献

Lang, D.E.,Morris, J.S.,Rowley, M.,Torres, M.A.,Maksimovich, V.A.,Facchini, P.J.,Ng, K.K.S.
Structure-function studies of tetrahydroprotoberberineN-methyltransferase reveal the molecular basis of stereoselective substrate recognition.
J.Biol.Chem., 294:14482-14498, 2019

PubMed Abstract: Benzylisoquinoline alkaloids (BIAs) are a structurally diverse class of plant-specialized metabolites that have been particularly well-studied in the order Ranunculales. The -methyltransferases (NMTs) in BIA biosynthesis can be divided into three groups according to substrate specificity and amino acid sequence. Here, we report the first crystal structures of enzyme complexes from the tetrahydroprotoberberine NMT (TNMT) subclass, specifically for TNMT from the yellow horned poppy (). TNMT was co-crystallized with the cofactor -adenosyl-l-methionine ( = 1.6 Å), the product -adenosyl-l-homocysteine ( = 1.8 Å), or in complex with -adenosyl-l-homocysteine and ()--methylstylopine = 1.8 Å). These structures reveal for the first time how a mostly hydrophobic L-shaped substrate recognition pocket selects for the ()- configuration of the two central six-membered rings in protoberberine BIA compounds. Mutagenesis studies confirm and functionally define the roles of several highly-conserved residues within and near the TNMT-active site. The substrate specificity of TNMT enzymes appears to arise from the arrangement of subgroup-specific stereospecific recognition elements relative to catalytic elements that are more widely-conserved among all BIA NMTs. The binding mode of protoberberine compounds to TNMT appears to be similar to coclaurine NMT, with the isoquinoline rings buried deepest in the binding pocket. This binding mode differs from that of pavine NMT, in which the benzyl ring is bound more deeply than the isoquinoline rings. The insights into substrate recognition and catalysis provided here form a sound basis for the rational engineering of NMT enzymes for chemoenzymatic synthesis and metabolic engineering.

PubMed: 31395658
DOI: 10.1074/jbc.RA119.009214

実験手法

X-RAY DIFFRACTION (1.6 Å)