2XLP

Joint-functions of protein residues and NADP(H) in oxygen-activation by flavin-containing monooxygenase: Asn78Ser mutant

Summary for 2XLP

• Entry DOI: 10.2210/pdb2xlp/pdb
• Related: 2VQ7 2VQB 2XLR 2XLS 2XLT 2XLU
• Descriptor: FLAVIN-CONTAINING MONOOXYGENASE, FLAVIN-ADENINE DINUCLEOTIDE, NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE, ... (6 entities in total)
• Functional Keywords: oxidoreductase, trimethyaminuria
• Biological source: METHYLOPHAGA AMINISULFIDIVORANS
• Total number of polymer chains: 4
• Total formula weight: 220854.56

Authors

Orru, R.,Fraaije, M.W.,Mattevi, A. (deposition date: 2010-07-21, release date: 2010-09-15, Last modification date: 2023-12-20)

Primary citation

Orru, R.,Pazmino, D.E.,Fraaije, M.W.,Mattevi, A.
Joint functions of protein residues and NADP(H) in oxygen activation by flavin-containing monooxygenase.
J. Biol. Chem., 285:35021-35028, 2010

PubMed Abstract: The reactivity of flavoenzymes with dioxygen is at the heart of a number of biochemical reactions with far reaching implications for cell physiology and pathology. Flavin-containing monooxygenases are an attractive model system to study flavin-mediated oxygenation. In these enzymes, the NADP(H) cofactor is essential for stabilizing the flavin intermediate, which activates dioxygen and makes it ready to react with the substrate undergoing oxygenation. Our studies combine site-directed mutagenesis with the usage of NADP(+) analogues to dissect the specific roles of the cofactors and surrounding protein matrix. The highlight of this "double-engineering" approach is that subtle alterations in the hydrogen bonding and stereochemical environment can drastically alter the efficiency and outcome of the reaction with oxygen. This is illustrated by the seemingly marginal replacement of an Asn to Ser in the oxygen-reacting site, which inactivates the enzyme by effectively converting it into an oxidase. These data rationalize the effect of mutations that cause enzyme deficiency in patients affected by the fish odor syndrome. A crucial role of NADP(+) in the oxygenation reaction is to shield the reacting flavin N5 atom by H-bond interactions. A Tyr residue functions as backdoor that stabilizes this crucial binding conformation of the nicotinamide cofactor. A general concept emerging from this analysis is that the two alternative pathways of flavoprotein-oxygen reactivity (oxidation versus monooxygenation) are predicted to have very similar activation barriers. The necessity of fine tuning the hydrogen-bonding, electrostatics, and accessibility of the flavin will represent a challenge for the design and development of oxidases and monoxygenases for biotechnological applications.

PubMed: 20807767
DOI: 10.1074/jbc.M110.161372

Experimental method

X-RAY DIFFRACTION (2.8 Å)