1pj7

From Proteopedia

Structure of dimethylglycine oxidase of Arthrobacter globiformis in complex with folinic acid

Overview

Here we report crystal structures of dimethylglycine oxidase (DMGO) from, the bacterium Arthrobacter globiformis, a bifunctional enzyme that, catalyzes the oxidation of N,N-dimethyl glycine and the formation of, 5,10-methylene tetrahydrofolate. The N-terminal region binds FAD, covalently and oxidizes dimethylglycine to a labile iminium intermediate., The C-terminal region binds tetrahydrofolate, comprises three domains, arranged in a ring-like structure and is related to the T-protein of the, glycine cleavage system. The complex with folinic acid indicates that this, enzyme selectively activates the N10 amino group for initial attack on the, substrate. Dead-end reactions with oxidized folate are avoided by the, strict stereochemical constraints imposed by the folate-binding funnel., The active sites in DMGO are approximately 40 A apart, connected by a, large irregular internal cavity. The tetrahydrofolate-binding funnel, serves as a transient entry-exit port, and access to the internal cavity, is controlled kinetically by tetrahydrofolate binding. The internal cavity, enables sequestration of the reactive iminium intermediate prior to, reaction with tetrahydrofolate and avoids formation of toxic formaldehyde., This mode of channelling in DMGO is distinct from other channelling, mechanisms.

About this Structure

1PJ7 is a Single protein structure of sequence from Arthrobacter globiformis with NA, FFO and FAD as ligands. Active as Dimethylglycine oxidase, with EC number 1.5.3.10 Full crystallographic information is available from OCA.

Reference

Channelling and formation of 'active' formaldehyde in dimethylglycine oxidase., Leys D, Basran J, Scrutton NS, EMBO J. 2003 Aug 15;22(16):4038-48. PMID:12912903

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