1;Preface;5 2;1 Berberine bridge enzyme and the family of bicovalent flavoenzymes;15 2.1;1.1 Introduction;15 2.2;1.2 The paradigm of bicovalent flavoenzymes: Berberine bridge enzyme (BBE) from Eschscholzia californica;21 2.3;1.3 The family of BBE-like enzymes in the plant kingdom: how many and what for?;25 2.4;1.4 The occurrence of BBE-like enzymes in fungi;34 2.5;1.5 BBE-like enzymes in bacteria: oxidative power for the biosynthesis of antibiotics;36 2.6;1.6 Conclusions;38 2.7;1.7 Acknowledgments;38 2.8;1.8 References;38 3;2 PutA and proline metabolism;45 3.1;2.1 Importance of proline metabolism;45 3.2;2.2 Proline utilization A (PutA) proteins;47 3.3;2.3 Three-dimensional structures of PutA and PutA domains;50 3.3.1;2.3.1 Structures of the catalytic domains of PutA;50 3.3.2;2.3.2 Crystal structure of a minimalist PutA;52 3.3.3;2.3.3 Solution structure of a trifunctional PutA and the role of the CTD;54 3.4;2.4 Reaction kinetics of PutA;54 3.4.1;2.4.1 Proline:ubiquinone oxidoreductase activity;55 3.4.2;2.4.2 Substrate channeling;57 3.5;2.5 DNA and membrane binding of trifunctional PutA;59 3.5.1;2.5.1 DNA binding;59 3.5.2;2.5.2 Membrane association;61 3.6;2.6 PutA functional switching;63 3.6.1;2.6.1 Redox-linked global conformational changes;63 3.6.2;2.6.2 Local structural changes near the flavin;64 3.6.3;2.6.3 Residues important for functional switching;65 3.7;2.7 Conclusions and future research directions;66 3.8;2.8 Acknowledgements;67 3.9;2.9 References;67 4;3 Flavoenzymes involved in non-redox reactions;71 4.1;3.1 Introduction;71 4.2;3.2 Flavoenzymes for which flavin cofactors likely play redox-based catalytic roles;72 4.2.1;3.2.1 Chorismate synthase;72 4.2.2;3.2.2 4-Hydroxybutyryl-CoA dehydratase;74 4.2.3;3.2.3 Polyunsaturated fatty acid isomerase;76 4.2.4;3.2.4 4'-Phosphopantothenoylcysteine decarboxylase;76 4.2.5;3.2.5 Other examples;79 4.3;3.3 Flavoenzymes for which flavin cofactors likely play non-redox catalytic roles;80 4.3.1;3.3.1 Type 2 isopentenyl diphosphate isomerase;80 4.3.2;3.3.2 UDP-galactopyranose mutase;82 4.4;3.4 Flavoenzymes for which flavin cofactors play uncertain, but probably catalytic roles;83 4.4.1;3.4.1 Lycopene cyclase;84 4.4.2;3.4.2 Carotene cis-trans isomerase;84 4.4.3;3.4.3 Fatty acid hydratase;86 4.4.4;3.4.4 2-Haloacrylate hydratase;86 4.5;3.5 Conclusions;86 4.6;3.6 References;87 5;4 Enzymes of FMN and FAD Metabolism;93 5.1;4.1 Introduction;93 5.2;4.2 Enzymes involved in the production of FMN and FAD in different organisms;94 5.3;4.3 FMN and FAD metabolism in yeasts and mammals;97 5.4;4.4 FMN and FAD metabolism in bacteria depends on a bifunctional enzyme;102 5.5;4.5 FMN and FAD metabolism in plants;105 5.6;4.6 Conclusions and future research directions;107 5.7;4.7 Acknowledgments;109 5.8;4.8 References;109 5.9;4.9 Abbreviations;113 6;5 Mechanisms of bacterial luciferase and related flavin reductases;115 6.1;5.1 Introduction;115 6.2;5.2 Luciferase mechanism overview;116 6.2.1;5.2.1 Mechanism of chemiexcitation;116 6.2.2;5.2.2 Identity of primary excited state and emitter;119 6.2.3;5.2.3 Multiple forms of 4a-hydroperoxy-FMNH intermediate II;120 6.2.4;5.2.4 Aldehyde substrate inhibition;121 6.3;5.3 Flavin reductases - general remarks;122 6.3.1;5.3.1 Mechanisms of flavin reductases in single-enzyme reactions;123 6.3.2;5.3.2 Mechanisms of luciferase:flavin reductase coupled reactions;123 6.3.3;5.3.3 Reduced flavin transfers in two-component monooxygenases in general;126 6.4;5.4 Acknowledgments;127 6.5;5.5 References;127 7;6 Amine and amino acid oxidases and dehydrogenases;133 7.1;6.1 Introduction;133 7.2;6.2 D-Amino acid oxidase and related enzymes;134 7.3;6.3 Monoamine oxidase and related enzymes;138 7.4;6.4 Trimethylamine dehydrogenase;145 7.5;6.5 Conclusions;147 7.6;6.6 Acknowledgments;147 7.7;6.7 References;147 8;7 Monoamine oxidases A and B: membrane-bound flavoenzymes of medical importance;153 8.1;7.1 Introduction;153 8.2;7.2 Structural studies of MAO A and MAO B;155 8.3;7.3 Flavin cofactor p