flavin mononucleotide

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..The Gram-positive bacterium Bacillus subtilis has two representatives of a class of riboswitches that bind flavin mononucleotide (FMN)...

..Instead, flavin mononucleotide (FMN)-binding fluorescent proteins (FbFPs) are suitable for quantitative real-time in vivo assays under ..

..The studies reveal altered redox properties of the FAD in W676H CPR. The data are discussed in the context of previous stopped-flow studies of human CPR and the X-ray crystallographic structure of rat CPR...

..The results indicate that Phe181 cooperates with Tyr140 and Tyr178 to play a major role in the binding and stability of FMN...

..Alternatively, NADH oxidation, by the flavin mononucleotide in complex I, can be coupled to the reduction of hydrophilic electron acceptors, in non-energy-transducing ..

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Hypoxia is encountered frequently by pathogenic and apathogenic fungi. A codon-adapted gene encoding flavin mononucleotide-based fluorescent protein (CaFbFP) was expressed in Candida albicans and Saccharomyces cerevisiae...

..Analysis of the single mutants indicates that the proline to alanine substitution has no impact, but that both leucine to phenylalanine substitutions are essential for FMN binding and maximum stability of the enzyme...

..The biological implications of an attenuated mechanism of MS reactivation by MSR on methionine and folate metabolism are discussed...

..aeruginosa PAO1 and sequenced. It encoded a 381-amino-acid protein that was related to several reduced flavin mononucleotide (FMNH2)-dependent monooxygenases, and it was the second in an operon of three genes, which we have named ..

..However, they differ markedly from those of yeast and bacterial CPRs, pointing to an important evolutionary difference in electronic regulation of these enzymes...

..The invariant residues Asn36 and Glu86 are implicated in the catalysis...

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..A flavin mononucleotide (FMN)-dependent riboswitch from the ribDEAHT operon of Bacillus subtilis uses a transcription termination ..

The biosynthesis of several protein cofactors is subject to feedback regulation by riboswitches. Flavin mononucleotide (FMN)-specific riboswitches, also known as RFN elements, direct expression of bacterial genes involved in the ..

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..The unusual metal-binding site involves, in addition to the ADP phosphates, only the strictly conserved Thr45. This may explain the preference for zinc observed in vitro...

Thiamin and riboflavin are precursors of essential coenzymes-thiamin pyrophosphate (TPP) and flavin mononucleotide (FMN)/flavin adenine dinucleotide (FAD), respectively...

..domain that is found frequently in the 5'-untranslated regions of prokaryotic mRNAs that encode for flavin mononucleotide (FMN) biosynthesis and transport proteins...

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..3 10(-2) microM(-1) s(-1)). Both RibC enzymes synthesized RoFAD and RoFMN. The functional expression of S. davawensis ribC did not confer roseoflavin resistance to a ribC-defective B. subtilis strain...

..The isoalloxazine ring of the bound FMN is significantly non-planar. Our structure illuminates the essential functional roles played by the cofactor...

..Here, we show that a 35mer RNA aptamer for the cofactor flavin mononucleotide (FMN) identified by in vitro evolution can be computationally evolved to a mere 14mer structure containing ..

..Cloning of a complementary DNA for brain nitric oxide synthase reveals recognition sites for NADPH, FAD, flavin mononucleotide and calmodulin as well as phosphorylation sites, indicating that the synthase is regulated by many ..

..However, novel interactions involving ARG111, GLY113 and SER317 were also observed...

..The enzyme catalyzed NADH-dependent reduction of flavin mononucleotide (FMN), and the K(m) values for NADH and FMN were 208 and 10.8 microM, respectively...

..These findings were correlated with the protein structure in order to contribute to a better understanding of the structure-function relationships in flavoredoxin...

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..Bacillus subtilis and Pseudomonas putida that contain light-oxygen-voltage-sensing domains, we engineered flavin mononucleotide-based fluorescent proteins that can be used as fluorescent reporters in both aerobic and anaerobic ..

..The purified enzyme had a typical flavoprotein absorption spectrum and flavin mononucleotide (FMN) was identified as a prosthetic group, non-covalently bound in a molar ratio of 1:1...

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..The structures of flavin mononucleotide (FMN) and pyridoxal 5'-phosphate (PLP) bound separately to Rv1155 have been determined at 2.2 and 1...

..This, together with the high degree of disorder observed in the FMN domain of all three mutant structures, suggests that conformational changes occur during catalysis...

..Despite overall structural resemblance of NR1 and CPR, our studies reveal thermodynamic similarities but major kinetic differences in the electron transfer reactions catalysed by the flavin-binding domains...

..The prokaryotic FAD synthetase family - a group of bifunctional enzymes that catalyse riboflavin phosphorylation and FMN adenylylation within a single polypeptide chain- was analysed in terms of sequence and structure...

..These data led us to conclude that the sodium-dependent step within the Na+-NQR is located between the noncovalently bound FAD and the covalently bound FMN...

..In contrast, in NqrC and NqrB the flavins are located in a cytoplasmic loop. This topological analysis suggests that there may be mechanistic differences between the Rnf and Na+-NQR complexes...

..Thus, this constitutes an example on how structural modules found within partner proteins from an electron transfer pathway can be combined in a single polypeptide chain achieving identical catalytic activities...

..The data indicate a more favorable formation of the active intermediate FMNH2 in the iNOS flavin domain...

..The analytical results demonstrated the feasibility of using the reported techniques to detect the chemical signature of life in barren desert sand samples...

..7 when free in solution. The pyridinium ion of 7 stabilizes the anionic form of reduced flavin analog and provides a dielectric medium more closely resemblingthat experienced by the flavin analog free in solution...

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..The redox properties of MSR are discussed in relation to other members of the diflavin oxidoreductase family and the mechanism of electron transfer...

..Availability of a stable NADPH-cytochrome P450 reductase capable of donating only a single electron to its redox partners provides a unique tool for investigating the electron-transfer properties of an intact reductase molecule...

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..On the basis of these data, we propose a common model for the catalytic cycle of both CaM-bound iNOS reductase domain and CPR...

..Our results reveal that the CT exerts both multifaceted and regiospecific effects on catalytic activities and related behaviors, and thus provide new insights into mechanisms that regulate nNOS catalysis...

..a shift in the rate-limiting step, indicating that the NOS C termini interrupt electron flux between flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) and/or the electron acceptors...

..POR is a flavoprotein that contains both flavin mononucleotide and flavin adenine dinucleotide as cofactors and uses NADPH as the source of electrons...

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..The flavin-semiquinone further reduces and the reduced flavin re-oxidizes back in the dark. A photo-dynamics scheme is presented and relevant quantum efficiencies and time constants are determined...

..precursor diacetyl but not in the presence of the downstream products flavin adenine dinucleotide and flavin mononucleotide. Riboflavin uptake was unaffected in the ribB mutant under iron-limited conditions but was lower in both ..

..These effects are discussed on the bases of the X-ray structures of some of the Fld mutants, suggesting that in Anabaena Fld the structural control of both electron transfer steps is much more subtle than in other Flds...

..Understanding the genetic and biochemical basis of POR-mediated drug metabolism will provide valuable information about possible differences in P450-mediated reactions among the individuals carrying a variant or polymorphic form of POR...

..for phototropins are two LOV domains which, when expressed in heterologous systems, each carry a single flavin mononucleotide (FMN) chromophore...

..polypeptides of other GltS forms, and involves: (i) an Ntn-type amidotransferase domain and (ii) a flavin mononucleotide-containing (beta/alpha)(8) barrel synthase domain connected by (iii) a approximately 30 A-long ..

..e. enhanced at low coenzyme concentration) observed in stopped-flow studies. The data are discussed in the context of previous kinetic studies and of the crystallographic structure of rat CPR...

..This model is also likely to apply to related enzymes such as cytochrome P450 reductase...

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..In this study, an RNA aptamer isolated and amplified on the basis of its affinity for flavin mononucleotide (FMN) was covalently bound to the inner walls of fused-silica capillaries...

..It is likely that differences in their relative affinities for the redox partner, methionine synthase, underlie the differences in the relative efficiencies of reductive activation exhibited by the variants...

..A detailed reanalysis shows that the data are in fact consistent with a simple single-binding-site model in which reversible hydride transfer causes the observed effect. Data for the related systems are also discussed...

..Analysis of our results combined with other analyses in the literature suggests that the heme domain of either monomer may accept electrons from the reduced FMN domain...

..From potentiometric studies, the reduction of the 2Fe-2S center and the reduction of the FMN occur concomitantly. The study provides a detailed thermodynamic framework for electron transfer in this complex iron-sulfur flavoprotein...

..spectroelectrochemistry to the quinone/semiquinone and semiquinone/hydroquinone couples of the protein's flavin mononucleotide (FMN) redox cofactor...

..According to literature data, it must also be present in other members of the family of L-2-hydroxy acid-oxidizing enzymes...

..Thus, a movement of the FMN-binding domain relative to the rest of the enzyme may be a requirement for its optimal positioning relative to both the FNR-like module and the beta-subunit...

..fourth sheet strand and the start of the third helix alter the environment of the pyrimidine end of the flavin mononucleotide ring...

..There is iron associated with the alpha-subunit, but placement of the nickel and FAD has not been established...

..Moreover, the FMN prosthetic group in SiR-FP23 and native SiR-FP is compared to that of cytochrome P450 reductase and bacterial cytochrome P450, which also contain one FAD and one FMN per polypeptide chain...

..Due to this process the overall reaction can start with the unquenched excited FAD* triplet state as an intermediate which is about 30 kJ/mol lower in energy than the dark reaction...

..The NfsB catalysis obeys the ping pong Bi-Bi mechanism. The Km value for NADH varied depending on the second substrate used...

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..8-6.3 and reflects either deprotonation of the reduced flavin or binding of orotate; this step is followed by hydride transfer to C6 and general acid-assisted protonation (pK of 9.1 +/- 0.2) at C5 of the product...

..There is only one conserved cysteine found among these enzymes, suggesting that Cys308 is the covalent flavin attachment site in MTOX...

..Interactions for flavin substrates are instead provided by a hydrophobic isoalloxazine binding site that also contains a serine and a threonine, which form hydrogen bonds to the isoalloxazine of bound riboflavin in a substrate complex...

..The resulting protein could no longer reduce cytochrome c, but could reduce 2,6-dichloroindophenol at a reduced rate...

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..DHODB is a heterotetramer composed of two different proteins (PyrDB and PyrK) and three different cofactors: FMN, FAD, and a [2Fe-2S] cluster...

..The mechanism of reduced flavin transfer appears to be delicately controlled by both flavin reductase and luciferase in the couple rather than unilaterally by either enzyme species...

..Noble, M., Robledo, L., Daff, S., and Chapman, S. (2001) Biochemistry 40, 1956-1963]...

..et al. (2000) Structure 8, 1299-1308]...

..This is the first example that the flavin is linked to a threonine residue. The amino acid sequence around the flavin-linked threonine was well conserved between NqrB and NqrC. Identification of the flavin group is in progress...

..The R203A mutant results in a 33-fold increase in the K(m) value for NADPH indicating that the side chain of Arg(203) plays a key role in binding NADPH possibly to interact with the 2'-phosphate group...

..This result, together with the sequence homology between SiR-FP and NADPH-cytochrome P-450 reductase, suggests a new model for the structure of the protein with one FMN and one FAD prosthetic group per alpha subunit...

..This study was carried out to investigate whether probiotic and traditional yoghurt bacteria are able to influence the status of different B vitamins (B(1), B(2), B(6)) in young healthy women...

..the free riboflavin, but in most biological materials it occurs predominantly in the form of 2 coenzymes, flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD)...

..Measurement of the various forms of these vitamins may be useful for the study of hyperhomocysteinemia as well as for the assessment of vitamin status...

..taurus complex I, respectively, and has the requisite structural features to be able to bind one flavin mononucleotide, one NAD, and three [4Fe-4S] clusters...

Glycolate oxidase (GO; (S)-2-hydroxyacid oxidase, EC 1.1.3.15) is a flavin mononucleotide (FMN)-dependent enzyme, which catalyzes the oxidation of 2-hydroxy carboxylic acids to the corresponding 2-keto acids...

..NADH is oxidized by a noncovalently bound flavin mononucleotide (FMN), then seven iron-sulfur clusters transfer the two electrons to quinone, and four protons are pumped ..

The biosynthesis pathway for riboflavin (vitamin B(2)), the precursor of the essential cofactors flavin mononucleotide and flavin adenine dinucleotide, is present in bacteria and plants but is absent in vertebrates...

..is applied as a robust single method to analyze trace amounts of three flavin derivatives, riboflavin, flavin mononucleotide (FMN), and flavin adenine dinucleotide (FAD), from several types of samples including bacterial cell ..

..The post-translationally incorporated chromophore is flavin mononucleotide (FMN). Upon absorption of blue light, LOV domains undergo a photocycle that activates a Ser/Thr kinase...

..Finally, the importance of some recent experimental and theoretical developments for the study of flavodoxin folding is briefly discussed...

..Our study was trying to determine for the first time, if the viable bacteria of probiotic yoghurt are able to influence the parameters of the B-vitamin (B(1), B(2), B(6)) status of the healthy adult human...

..HPLC analyses identified flavin mononucleotide as cofactor of the rat enzyme; UV-vis and fluorometric analyses verified a flavin/protein ratio of 0.8-1...

..Two Fprs prefer a native ferric chelator to a synthetic ferric chelator and utilize free flavin mononucleotide (FMN) as an electron carrier...

..Crystals of the eNOS heme domain diffract to 2.5A and smaller crystals of the nNOS and iNOS heme domains have been obtained. Our initial goal will be to solve the crystal structure of the eNOS heme domain. ..

..Relevance: By clarifying how nitric oxide production occurs and is regulated, our work may help to develop treatments for human diseases that involve making too much or too little nitric oxide. ..

..Our studies of the rates of the chemical reactions will identify important parts of the proteins, how they move during reactions, how they speed the synthesis of products, and how these reactions might be blocked. ..

..amino-acid, 78 kDa protein that contains two flavins, a flavin adenine dinucleotide moiety (FAD), and a flavin mononucleotide (FMN). There is substantial genetic variation in the hepatic P450 enzymes...

..amino-acid, 78 kDa protein that contains two flavins, a flavin adenine dinucleotide moiety (FAD), and a flavin mononucleotide (FMN). There is substantial genetic variation in the hepatic P450 enzymes...

..This type 2 IPP isomerase, unlike the well-studied type 1 enzymes, depends on flavin mononucleotide and NADPH for activity...

..The synthesis of NO is critically influenced by various cofactors such as tetrahydrobiopterin, flavin mononucleotide and flavin adenine dinucleotide, the presence of reduced thiols, and the endogenous NOS inhibitor ..

A recent report describes the cloning and preliminary characterization of an unusual flavin mononucleotide (FMN) dependent enzyme, the type II isopentenyl diphosphate (IPP) isomerase...

..a copper-ion cofactor, flavodoxin, a protein with an a/b doubly-wound topology coordinating an organic flavin mononucleotide (FMN), and cytochrome f, a b-sheet protein covalently linked to a heme...

..Riboswitches that respond to flavin mononucleotide (FMN), adenine, and glycine are the current targets of study...

..Riboswitches that respond to flavin mononucleotide (FMN), adenine, and glycine are the current targets of study...

..of NO synthesis in endothelial and neuronal NOS (eNOS and nNOS) requires a conformational change of the flavin mononucleotide (FMN) domain from its original electron- accepting (input) state to a new electron-donating (output) state...

..of NO synthesis in endothelial and neuronal NOS (eNOS and nNOS) requires a conformational change of the flavin mononucleotide (FMN) domain from its original electron- accepting (input) state to a new electron-donating (output) state...

..2) Generate truncated NOS to analyze domain interaction by crystallography.(3) Evaluate a role for charged surface residues in domain docking,(4) Evaluate three candidate pathways for electron delivery to heme and/or H4B. ..

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..We will determine the substrate specificities of selected model DUSs and probe the interactions of the protein and tRNA by chemical and biophysical means. Project Description Page 6 ..

..By clarifying how nitric oxide production is regulated at the enzyme level, our work may help to develop treatments for human diseases that involve making too much or too little nitric oxide. ..

..Especially important is the role played by P450s in drug metabolism, cancer, and the biosynthesis of critical steroid intermediates and antibiotics. ..

..Together, this will provide a comprehensive picture regarding how dimer formation activates iNOS, and how it can be controlled. ..

..Our studies of the rates of the chemical reactions will identify important parts of the proteins, how they move during reactions, how they speed the synthesis of products, and how these reactions might be blocked. ..

..The primary methods to employed are protein engineering coupled with crystallography and other biophysical approaches such as EPR spectroscopy and flash photolysis methods for following rapid reactions. ..

..This quantitative treatment of the literature data on biochemical reactions will uncover errors because deltafG'0 values can be determined by use of two or more biochemical reactions, which should give the same answer. ..

..Relevance: By clarifying how nitric oxide production occurs and is regulated, our work may help to develop treatments for human diseases that involve making too much or too little nitric oxide. ..

..Another objective is to use new concepts in biochemical thermodynamics to investigate coupling of reactions by enzymes, missing reactions in systems like glycolysis, muscle, and chemosmotic theory. ..

..In the next phase, DNA-based cross-reactive sensors for oligosaccharides will be incorporated into arrays to expand the panel of metabolites that could be profiled in a single-step assay. ..

..These will test understanding of kinetic control mechanism and reveal how NOS products and function can change when key kinetic parameters deviate from their natural ranges. ..

..At the end of this funding period, we will provide proof-of-concept experiments for the complete paradigm, and either eliminate or protect any one or two out of three model cell lines, based on their immunophenotype fingerprints. ..

..By clarifying how nitric oxide production is regulated at the enzyme level, our work may help to develop treatments for human diseases that involve making too much or too little nitric oxide. ..

..These include markers for disease progression, treatment efficacy, and high-throughput drug discovery. Our work with non-neuronal tissue may identify markers that provide far more-convenient monitoring. ..

..The ubiquinone isoprenyl chain-length preference of the E. coli enzyme will be determined. Enzyme-ligand interactions will be probed with Raman spectroscopy. ..