PDBsum entry 1w4x

Oxygenase

PDB id: 1w4x

Contents

Protein chain

533 a.a. *

Ligands

FAD

SO4

Waters ×535

* Residue conservation analysis

PDB id:

1w4x

Name:

Oxygenase

Title:

Phenylacetone monooxygenase, a baeyer-villiger monooxygenase

Structure:

Phenylacetone monooxygenase. Chain: a. Engineered: yes

Source:

Thermobifida fusca. Organism_taxid: 2021. Expressed in: escherichia coli. Expression_system_taxid: 511693.

Resolution:

1.70Å R-factor: 0.213 R-free: 0.244

Authors:

E.Malito,A.Alfieri,A.Mattevi

Key ref:

E.Malito et al. (2004). Crystal structure of a Baeyer-Villiger monooxygenase. Proc Natl Acad Sci U S A, 101, 13157-13162. PubMed id: 15328411 DOI: 10.1073/pnas.0404538101

Date:

03-Aug-04 Release date: 02-Sep-04

Protein chain

Q47PU3  (PAMO_THEFY) -  Phenylacetone monooxygenase from Thermobifida fusca (strain YX)

Seq: 542 a.a.

Struc: 533 a.a.

Enzyme reactions

• Enzyme class: E.C.1.14.13.92 - phenylacetone monooxygenase.
• Reaction: phenylacetone + NADPH + O2 + H⁺ = benzyl acetate + NADP⁺ + H2O
• Cofactor: FAD

FAD (Bound ligand (Het Group name = FAD) corresponds exactly)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1073/pnas.0404538101

Proc Natl Acad Sci U S A 101:13157-13162 (2004)

PubMed id: 15328411

Crystal structure of a Baeyer-Villiger monooxygenase.

E.Malito, A.Alfieri, M.W.Fraaije, A.Mattevi.

ABSTRACT

Flavin-containing Baeyer-Villiger monooxygenases employ NADPH and molecular oxygen to catalyze the insertion of an oxygen atom into a carbon-carbon bond of a carbonylic substrate. These enzymes can potentially be exploited in a variety of biocatalytic applications given the wide use of Baeyer-Villiger reactions in synthetic organic chemistry. The catalytic activity of these enzymes involves the formation of two crucial intermediates: a flavin peroxide generated by the reaction of the reduced flavin with molecular oxygen and the "Criegee" intermediate resulting from the attack of the flavin peroxide onto the substrate that is being oxygenated. The crystal structure of phenylacetone monooxygenase, a Baeyer-Villiger monooxygenase from the thermophilic bacterium Thermobifida fusca, exhibits a two-domain architecture resembling that of the disulfide oxidoreductases. The active site is located in a cleft at the domain interface. An arginine residue lays above the flavin ring in a position suited to stabilize the negatively charged flavin-peroxide and Criegee intermediates. This amino acid residue is predicted to exist in two positions; the "IN" position found in the crystal structure and an "OUT" position that allows NADPH to approach the flavin to reduce the cofactor. Domain rotations are proposed to bring about the conformational changes involved in catalysis. The structural studies highlight the functional complexity of this class of flavoenzymes, which coordinate the binding of three substrates (molecular oxygen, NADPH, and phenylacetone) in proximity of the flavin cofactor with formation of two distinct catalytic intermediates.

Selected figure(s)

Figure 1.
Fig. 1. Schematic representation of the overall catalytic reaction of the Baeyer-Villiger monooxygenases with reference to PAMO (mainly based on the kinetic analysis by Sheng et al. (7) of cyclohexanone monooxygenase). The atomic numbering of the flavin ring is shown on the left (corresponding to the initial step of the reaction).

Figure 4.
Fig. 4. Stereo view of the flavin-binding site. The orientation is approximately the same as that of Fig. 3. The flavin has a planar conformation although its N10 atom exhibits a considerable degree of pyramidalization, which positions the C1 atom of the ribityl chain out of the flavin plane. Carbons are shown in black, oxygens are shown in red, and nitrogens are shown in blue. Ordered water molecules are shown as red spheres. H-bond interactions are outlined by the dashed lines.

Figures were selected by an automated process.