1zch

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spinqualitylabelsall models 1zch, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Structure of the hypothetical oxidoreductase YcnD from Bacillus subtilis

Overview

YcnD from the gram-positive bacterium Bacillus subtilis is a member of a, family of bacterial proteins that act as NADH- and/or NADPH-dependent, oxidoreductases. Here, we report for the first time on the biochemical, characterization of the purified protein, demonstrating that YcnD is an, FMN-containing enzyme that can be reduced by NADH or NADPH (Km = 6.4 and, 4.4 microM, respectively). In the presence of free FMN as the, electron-accepting substrate, the latter reductant showed a ping-pong, Bi-Bi reaction mechanism, whereas utilization of NADH is competitively, inhibited by this substrate. This finding suggests that NADPH is the, physiological reductant of the enzyme. We also show that YcnD reduces, nitro-organic compounds, chromate, and a series of azo dyes. The reduction, of azo dyes appears to be mediated by free reduced FMN because the, reaction is considerably slower in its absence. Structure determination by, X-ray crystallography revealed that YcnD folds into a three layer, alpha-beta-alpha sandwich strongly resembling the topology of the NADH, oxidase superfamily. Similar to homologous bacterial oxidoreductase, YcnD, forms homodimers with an extended dimer interface. The biochemical data, and the structure are discussed in light of the putative physiological, function of YcnD as an oxidoreductase delivering reduced FMN to enzymes, that require the reduced cofactor for activity.

About this Structure

1ZCH is a Single protein structure of sequence from Bacillus subtilis with CL, CA and FMN as ligands. Full crystallographic information is available from OCA.

Reference

Structure and function of YcnD from Bacillus subtilis, a flavin-containing oxidoreductase., Morokutti A, Lyskowski A, Sollner S, Pointner E, Fitzpatrick TB, Kratky C, Gruber K, Macheroux P, Biochemistry. 2005 Oct 25;44(42):13724-33. PMID:16229462

Page seeded by OCA on Wed Nov 21 07:23:01 2007