The flavoenzyme azobenzene reductase AzoR from Escherichia coli binds roseoflavin mononucleotide (RoFMN) with high affinity and is less active in its RoFMN form
| Autor: | Tanja Knaus, Shinobu Nakanishi, Tomoko Mase, Peter Macheroux, Alexandra Binter, Masaru Tanokura, Takuya Miyakawa, Matthias Mack, Tilo Mathes, Simone Langer |
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| Rok vydání: | 2013 |
| Předmět: |
animal structures
Stereochemistry Riboflavin Flavin mononucleotide Azobenzene reductase Plasma protein binding medicine.disease_cause Crystallography X-Ray Biochemistry Cofactor chemistry.chemical_compound Enzyme activator Apoenzymes medicine Escherichia coli NADH NADPH Oxidoreductases chemistry.chemical_classification biology Escherichia coli Proteins Enzyme Activation Enzyme chemistry biology.protein Protein Multimerization Protein Binding |
| Zdroj: | Biochemistry. 52(25) |
| ISSN: | 1520-4995 |
| Popis: | The Gram-positive bacterium Streptomyces davawensis is the only organism known to produce the antibiotic roseoflavin. Roseoflavin is a structural riboflavin analogue and is converted to the flavin mononucleotide (FMN) analogue roseoflavin mononucleotide (RoFMN) by flavokinase. FMN-dependent homodimeric azobenzene reductase (AzoR) (EC 1.7.1.6) from Escherichia coli was analyzed as a model enzyme. In vivo and in vitro experiments revealed that RoFMN binds to the AzoR apoenzyme with an even higher affinity compared to that of the “natural” cofactor FMN. Structural analysis (at a resolution of 1.07 A) revealed that RoFMN binding did not affect the overall topology of the enzyme and also did not interfere with dimerization of AzoR. The AzoR–RoFMN holoenzyme complex was found to be less active (30% of AzoR–FMN activity) in a standard assay. We provide evidence that the different physicochemical properties of RoFMN are responsible for its reduced cofactor activity. |
| Databáze: | OpenAIRE |
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